I get the sense that every catering/event contract is a bit different. If points are of maximum importance you might be able to trade off something else but I'm not sure I'd try to do it.

With my Marriott reception back in the day, the best "extras" I received were the on-property room upgrades during the event. The Presidential Suite plus a couple other nice suites for people in my party... The catering manager seems to have a lot of direct power there - probably a simple phone call or two to a colleague down the hall. Getting some sort of unusual points deal into the contract probably involves more people, more hassle, more paperwork. Maybe a card you don't want to play...