This has probably been asked before, but i thought ive read that if the room rate changes in any way (such as the hotel rebooking you into a higher category room for free) then the 4th night free benefit gets messed up. how are extra charges from the hotel stay handled (spa, restaurant, etc.)? I'm assuming that's ok, but please let me know asap if those have to go on a separate card so that 4th night free benefit stays valid.

Thank you