Yes you can either call Marriott Rewards or Ritz reservations directly to make the booking then Marriott Rewards to order the certificates...sometimes I have called Marriott and there are no rooms available and then called the Ritz and they show them available...so be aware of that...either can make the reservation for you. Then a week prior, I have them send the certificates directly to the Ritz...I always call before to ensure the Ritz has received them to ensure a smooth check in process. Please note that the points are much higher to stay at a Ritz. For example I am using 250k points for 7 night at the Ritz in Cayman but that is a higher tier hotel compared to the Ritz in Jamaica where it would be 175k.