How to use Post Indexer to only grab blog posts from Supporter Blogs

I'm trying to use post indexer to only grab blog posts from supporter blogs and I can't figure out a way to do it.

Is there a table that I would be able to check to basically say

If the blog that posted this is a supporter blog, then grab it, if not, leave it alone.

This way we can display only supporter blogs on our main site with Recent Global Posts and we can create a Supporter only feed, with Recent Global Posts Feed.