I have my columns for the parent and child tables declared in code.  I load the data and bind at runtime.  However I cannot access anything but the parent band.  Here is the xaml.  In this case gridTransaction.ColumnLayouts(1) or gridTransaction.ColumnLayouts("TransactionCodings") is nothing at runtime.

       <igGrid:XamWebGrid HorizontalAlignment="Left" Margin="0,85,0,0" Name="gridTransaction" VerticalAlignment="Top" AutoGenerateColumns="False">
            <igGrid:XamWebGrid.Columns>
                <igGrid:TextColumn Key="TransactionDate" HeaderText="Trans Date" FormatString="{}{0:d}" HorizontalContentAlignment="Right" />
                <igGrid:UnboundColumn Key="Merchant" ValueConverter="{StaticResource TransactionMerchant}"/>
                <igGrid:TextColumn Key="MCCNum" HeaderText="Category"/>
                <igGrid:TextColumn Key="PostDate" HeaderText="Post Date" FormatString="{}{0:d}" HorizontalContentAlignment="Right"/>
                <igGrid:TextColumn Key="TotalDue" HeaderText="Total Due" FormatString="{}{0:c}" HorizontalContentAlignment="Right"/>
                <igGrid:TextColumn Key="Status" ValueConverter="{StaticResource TransactionStatus}" HeaderText="Status"/>
                <igGrid:ColumnLayout Key="TransactionCodings">
                    <igGrid:ColumnLayout.Columns>
                        <igGrid:TextColumn Key="CodingType" HeaderText="Code To" />
                        <igGrid:TextColumn Key="Company" />
                        <igGrid:TextColumn Key="JobNum" HeaderText="Job"/>
                        <igGrid:TextColumn Key="JobPhase" HeaderText="Phase" />
                        <igGrid:TextColumn Key="JobCostType" HeaderText="Cost Type" />
                        <igGrid:TextColumn Key="EquipmentNum" HeaderText="Equipment" />
                        <igGrid:TextColumn Key="CostCategory" HeaderText="Category" />
                        <igGrid:TextColumn Key="GLAccount" HeaderText="Account" />
                        <igGrid:UnboundColumn Key="Description" />
                        <igGrid:TextColumn Key="Amount" FormatString="{}{0:c}" HorizontalContentAlignment="Right" />
                    </igGrid:ColumnLayout.Columns>
                </igGrid:ColumnLayout>
            </igGrid:XamWebGrid.Columns>
        </igGrid:XamWebGrid>