I don't know for sure, but I'd guess the bowl of chowder is included on the DDP, but as an entree. Probably not the most "bang for your buck" as credits go, but if that's what you want, what the heck? It seems to me I was able to get a bowl of vegetarian chili at POR food court as an entree on the DDP. With a dessert, it was plenty for lunch.
At CHH, you can also get the half sandwich and cup of chowder on the DDP, if any of the sandwiches interest you. And last year (2006) the person in front of me didn't want a dessert and was offered a cup of chowder instead. I don't know whether they would still allow this, but half sandwich + 2 cups (1 with entree, 1 for dessert) might be close to a bowl, if you don't mind the half sandwich instead of dessert.