I think with Citibank and MBNA it depends on what are you are in. I applied for both last Nov., Dec., and they both pulled Experian for me. Yuck...my worst report. I did get BofA, and they pulled Trans Union. They needed a second report and asked me which one to use, I directed them to Equifax
Citbank pulls based on your location, they pull EXP for Mass. but TU for NH. What state are you from?
Sears retail card. Chase and Citi use Trans Union a lot for me, but also Experian for account reviews and limit increases.