No Marriott's in Geneva, there are properties in Basel, Zurich, and a new one in Lucerne. If you meetings are near a train station you could commute, but that could make for a long day. I new people who did commute from Zurich Marriott to Basel meetings and did not mind the one hour commute, each way.
Jerry is right... no Marriott's in Geneva.
I had some Holiday Inn points from a 5 week stay. So, I applied for the Priority Club credit card. Between my points and the credit card sign-up bonus points, I had more than enough points for a 2 night stay at the Intercontinental in Geneva.
Or, there is a Hilton in Evian les Bains (France) which sits on Lake Geneva not too far from Geneva... it's where the Evian water comes from!