Here is the solution.

<igDP:XamDataGrid.Resources>
<Style x:Key="Prop1Style" TargetType="{x:Type igDP:CellValuePresenter}">
<Setter Property="ToolTip">
<Setter.Value>
<StackPanel>
<TextBlock Text="{Binding DataItem.Prop1}" />
</StackPanel>
</Setter.Value>
</Setter>
</Style>

<Style x:Key="Prop2Style" TargetType="{x:Type igDP:CellValuePresenter}">
<Setter Property="ToolTip">
<Setter.Value>
<StackPanel>
<TextBlock Text="{Binding DataItem.Prop2}" />
</StackPanel>
</Setter.Value>
</Setter>
</Style>

</igDP:XamDataGrid.Resources>

<igDP:XamDataGrid.FieldLayouts>
<igDP:FieldLayout>
<igDP:FieldLayout.Fields>

<igDP:Field Name="Prop1" Label="Name">
<igDP:Field.Settings>
<igDP:FieldSettings CellValuePresenterStyle="{StaticResource Prop1Style}">
</igDP:FieldSettings>
</igDP:Field.Settings>
</igDP:Field>
<igDP:Field Name="Prop2" Label="Age">
<igDP:Field.Settings>
<igDP:FieldSettings CellValuePresenterStyle="{StaticResource Prop2Style}">
</igDP:FieldSettings>
</igDP:Field.Settings>
</igDP:Field>
</igDP:FieldLayout.Fields>
</igDP:FieldLayout>
</igDP:XamDataGrid.FieldLayouts>