Island Prime on Harbor Island does not have a guest dock. You can make prior arrangements next door at Sunroad Marina to dock and dine. Ask for Jim or Todd.
Same thing at Cabrillo Isle Marina... make prior arrangements for a guest slip and you can walk next door to a couple of hotels with a half dozen restaurants between them.
Bali Hai on Shelter Island has a large fairly well protected guest dock. The restaurant is recently remodeled and very nice.
The problem with some of the others (such as Anthony's downtown) is that they're adjacent to no speed zones, the docks are in bad shape... not protected from boat wakes. I wouldn't tie up anything larger than 30' at most of them.