The reason for this would be that both, Pizza Hut & Taco Bell (as well as KFC) are owned by the same company: Yum Brands.
Correct. It is even possible to find restraints that are dual or triple restaurants, serving food for all three.
Which is what the song is about.
You mean Queens and the Bay Area.
Actually, they are talking about combination pizza hut and taco bells, which are in the same building (and owned by the same parent company). So it is slightly different. They are literally the exact same location, not just close by.