I just received by physical mail a discount certificate valued at $100 which CIti give cardholders who meet a certain spending threshold during their credit card membership year and who also have kept the account open for at least 45 days after the year renews.

In the past I have called Citi and asked to cancel my AA mileage earning card around the anniversary, at which they have often given me a fee waiver for keeping the account open.

In this situation, would they waive the annual fee again (pro-rated for the remainder of the card membership year) now that I've got this certificate? Or are the two things mutually exclusive?

Do they invalidate the certificate if you receive the waiver? If so, could they tell if you use the certificate first and then call to try and get the annual fee waived afterwards?

Also: the $100 is discounted from the base airfare but not from taxes. Does it work for more than one traveler on a single PNR -- ie. if the base fare is below $100 but there are several pax on the PNR, would the full $100 go towards the total cost of all the tickets taken together?