Hyatt FFN requires use of MasterCard and they are stringent about it. For MC paid stays, you can see a record of "Master Card Charge" in your stay record online. No MasterCard means no FFN credit. So I guess they have a co-sponsor.
There really shouldn't be any complaints about using the sponsors card to qualify for the free weekend credit.
Amex used to sponsor FFN. A year or so ago, Hyatt switched to MasterCard. Hyatt doesn't have a co-branded credit card, so they might have a little more flexibility when finding a sponsor.
Anyway, FFN is a better promotion than free weekends anyway. (unlimited earning, easier to use, not restricted to weekends, but at a non-resort property, for midweek stay, you have to use 3 free nights, I believe.)
-David
[This message has been edited by LIH Prem (edited 06-20-2003).]