If you look at the (unecessary) $ 150 Food & Beverage Certificate you will read under Guest Instructions: Certificate is to be used on a future stay between 5/16/09 and 1/31/10. Independently from that, these certificates are only valid in conjunction with eligible stays.
However, you can quote DEL5K at your resort stay (special offer code good until 1/31/10) & you will receive $ 150 F&B credit for this current stay (and a one time 5K GP points bonus).