No post card offers yet, but on the web site, if you enter your bar code from your AP, then click on SeaWorld Florida, there is a link for DC, and here's what it says.
SeaWorld Orlando Passport Members, SeaWorld Orlando/Busch Gardens Tampa Bay Passport Members and SeaWorld Orlando/Busch Gardens Tampa Bay/Adventure Island Passport Members receive a special rate of $169.00 plus tax for the dolphin swim package, and $79.00 plus tax (valid through 2/28/02; $89.00 3/1 - 12/31/02) for the non-dolphin swim package.