Seafire Inn has one of my favorite vegetarian options. The SW website lists it as a veggie wrap, but I remember it being in a thick, multi-grain bun (unless they changed it).
Mango Joe's does have a wrap.
Spice Mill has a garden burger.
Terrace Garden Buffet has decent options for vegetarians. It is a pizza and pasta buffet.
They do also have those large, soft pretzels. One place I know for sure that sells them is Seaport Market (next to Seaport Pizza).