Imports System.ComponentModel
Imports System.ComponentModel.DataAnnotations
Imports System.ComponentModel.DataAnnotations.Schema

Public Class TaskCreateViewModel
    Public Sub New()
        Environments = New HashSet(Of EnvironmentModel)()
        EnvironmentsAvailable = New HashSet(Of EnvironmentAvailableModel)()
    End Sub
    Public Property Id As Long
    Public Property MilestoneId As Long
    <Required>
    <StringLength(250)>
    Public Property Title As String
    <Column(TypeName:="ntext")>
    Public Property Description As String
    Public Property WD As Byte
    Public Property SLA As Byte
    <DataType(DataType.Date)>
    <DisplayFormat(ApplyFormatInEditMode:=True, DataFormatString:="{0:yyyy-MM-dd}")>
    <DisplayName("Plannned end date")>
    <Required(ErrorMessage:="Plannned End Date can't be empty")>
    Public Property PlannedEndDate As Date
    <DataType(DataType.Time)>
    <DisplayFormat(ApplyFormatInEditMode:=True, DataFormatString:="{0:hh\:mm}")>
    <DisplayName("Plannned end time")>
    <Required(ErrorMessage:="Plannned End Time can't be empty")>
    Public Property PlannedEndTime As TimeSpan
    Public Overridable Property Environments As ICollection(Of EnvironmentModel)
    Public Overridable Property EnvironmentsAvailable As IEnumerable(Of EnvironmentAvailableModel)  [color=red]< ---- Вот то что хочу увидеть в контроллере POST[/color]
End Class

Public Class EnvironmentModel
    Public Property Id As Byte
    Public Property Name As String
End Class

Public Class EnvironmentAvailableModel
    Public Property Id As Byte
    Public Property Name As String
    Public Property IsSelected As Boolean
End Class

        Function Create() As ActionResult

            Try

                Mapper.CreateMap(Of Task, TaskCreateViewModel)().ForMember(Function(dest) dest.EnvironmentsAvailable, Sub(opt) opt.Ignore())

                Mapper.CreateMap(Of Environment, EnvironmentAvailableModel)().ForMember(Function(dest) dest.IsSelected, Sub(opt) opt.Ignore())

                Dim sourceEnvironmentsAvailable As IEnumerable(Of Environment) = db.Environments.ToList

                Dim modelEnvironmentsAvailable As IEnumerable(Of EnvironmentAvailableModel) = Mapper.Map(Of IEnumerable(Of Environment), IList(Of EnvironmentAvailableModel))(sourceEnvironmentsAvailable)

                Dim model As TaskCreateViewModel = Mapper.Map(Of Task, TaskCreateViewModel)(New Task)
                model.EnvironmentsAvailable = modelEnvironmentsAvailable
                
                ViewBag.MilestoneId = New SelectList(db.Milestones, "Id", "Title")
                ViewBag.Id = New SelectList(db.PreviousTasks, "Id", "Id")

                Return View(model)

            Catch ex As Exception
                Return View("Error", New HandleErrorInfo(ex, "Tasks", "Create GET"))
            End Try

        End Function

@ModelType TaskCreateViewModel 
@Code
    ViewData("Title") = "Create"
    Layout = "~/Views/Shared/_Layout.vbhtml"
End Code

<h2>Create</h2>

@Using (Html.BeginForm())
    @Html.AntiForgeryToken()

    @<div class="form-horizontal">
        <h4>Task</h4>
        <hr />
        @Html.ValidationSummary(True, "", New With {.class = "text-danger"})
        <div class="form-group">
            @Html.LabelFor(Function(model) model.MilestoneId, "MilestoneId", htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.DropDownList("MilestoneId", Nothing, htmlAttributes:=New With {.class = "form-control"})
                @Html.ValidationMessageFor(Function(model) model.MilestoneId, "", New With {.class = "text-danger"})
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.Title, htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.Title, New With {.htmlAttributes = New With {.class = "form-control"}})
                @Html.ValidationMessageFor(Function(model) model.Title, "", New With {.class = "text-danger"})
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.Description, htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.Description, New With {.htmlAttributes = New With {.class = "form-control"}})
                @Html.ValidationMessageFor(Function(model) model.Description, "", New With {.class = "text-danger"})
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.WD, htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.WD, New With {.htmlAttributes = New With {.class = "form-control"}})
                @Html.ValidationMessageFor(Function(model) model.WD, "", New With {.class = "text-danger"})
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.SLA, htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.SLA, New With {.htmlAttributes = New With {.class = "form-control"}})
                @Html.ValidationMessageFor(Function(model) model.SLA, "", New With {.class = "text-danger"})
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.PlannedEndDate, htmlAttributes:=New With {.class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.PlannedEndDate, New With { .htmlAttributes = New With { .class = "form-control" } })
                @Html.ValidationMessageFor(Function(model) model.PlannedEndDate, "", New With { .class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(Function(model) model.PlannedEndTime, htmlAttributes:= New With { .class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(Function(model) model.PlannedEndTime, New With { .htmlAttributes = New With { .class = "form-control" } })
                @Html.ValidationMessageFor(Function(model) model.PlannedEndTime, "", New With { .class = "text-danger" })
            </div>
        </div>


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

        @For index As Byte = 0 To Model.EnvironmentsAvailable.Count - 1

        @<div Class="form-group">
                @Html.DisplayFor(Function(model) model.EnvironmentsAvailable(index).Name, New With {.htmlAttributes = New With {.Class = "control-label col-md-2"}})
            <div Class="col-md-10">
                <div Class="checkbox">
                    @Html.EditorFor(Function(model) model.EnvironmentsAvailable(index).IsSelected)
                    @Html.ValidationMessageFor(Function(model) model.EnvironmentsAvailable(index).IsSelected, "", New With {.class = "text-danger"})
                </div>
            </div>
        </div>

        Next


PS. Делал так

    @if Model.EnvironmentsAvailable.Count > 0 then
        @<div Class="form-group">
            @For index As Byte = 0 To Model.EnvironmentsAvailable.Count - 1
            @Html.HiddenFor(Function(model) model.EnvironmentsAvailable(index).Id)
            @Html.CheckBoxFor(Function(model) model.EnvironmentsAvailable(index).IsSelected)
            @Html.DisplayFor(Function(model) model.EnvironmentsAvailable(index).Name)
                Next
            </div>
    End If

PSS. Делал через For Each. 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
End Using

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

@Section Scripts 
    @Scripts.Render("~/bundles/jqueryval")
End Section