Hi Greg and welcome to our forum,
One of the limitations of property promotion in Sharepoint is that you can't promote a collection of items. The properties are a flat table, so if you are trying to promote repeating items under one column in that table, it doesn't work. You can concatenate values into a string, but this isn't very useful.
This is one of the reasons why we advocate using SQL integrated into SharePoint. We developed the Database Accelerator to help "accelerate" this process. With SQL behind SharePoint, you can create reports where the child collections show up as a promoted group. The SQL reports will require some work to configure, but give you more power to display your data in a non-flat way. To try a free evaluation version of the DBXL Suite, check out
http://www.qdabra.com/proddetail.asp?prod=QDBXL1