Summary of Unique Table Relationship

After digging through many posts, I haven't been able to find a solution to this problem... Any help is appreciated.

I have 2 tables: 
Consumer
Vendors

Each consumer can work with many vendors and each vendor can work with many consumers. Within each vendor, we also capture the parent company related to that vendor. (E.G. Wal-Mart East has a parent company of Wal-Mart and Wal-Mart Texas also has a parent company of Wal-Mart.)

What we are trying to do is get a summary table that shows how many consumers work with the parent companies.

Example:

Consumer 1 works with Wal-Mart East and Wal-Mart Texas
Consumer 2 works with Wal-Mart East and Target and CVS
Consumer 3 works with Target

I'd like the summary report to show:

Parent Vendors :: Unique Consumers
Wal-Mart :: 2
Target :: 2
CVS :: 1