I do not believe you can bind a repeating table to multiple data sources. I know in other Microsoft development environments that would not be possible.
I have had a similar situation where I had two repeating groups in my schema, or two sharepoint lists in your case, and I wanted to display them visually as a single list. What I did was I stacked the two repeating lists and removed the footer for the top one and removed the header from the bottom one. You will have to do some other things but I was able to get it to look pretty nice visually.
Although, there are some disadvantages to this approach, which may not come into play since you are using a sharepoint list. If the repeating tables are editable, meaning the user can insert or delete rows, it does not work well unless you write your own insert and delete buttons and then orchestrate which repeating tables will be edited. If the end if the sharepoint lists are read-only this will work well.
Jason
http://www.k2distillery.com/