The rate I had included $100/night credit for incidental charges to the room. I had been told each $100 had to be spent the day it was credited or you lose it. When I checked-in, the Club 91 attendant told me that while I would see a $100/night credit, it would add up to $500 for me to spend as any amount through the week. That meant the $200 SPA massage charge was fully covered.
I am in the exact same situation, except it is $50/day credit. I too am staying on the Club 91 floor (or like you, with access to the lounge). I too have read elsewhere that the hotel is strict on "use it or lose it" per day charges. But you suggest that when checking in you were told otherwise. In the end, was the $100/day accumulated to $500/stay as you indicate above?