I believe that Sugar Ridge near Jolly Harbour has both rooms and Carmichael's restaurant which should always have veggie options. As well as the Aveda spa. There's also Mayday in Jolly Harbour itself.

In St John's there's a vegetarian place between Radcliffe Quay and Heritage Quay - you might have to hunt around for it as I forget the name, but saw it listed in a magazine last week. I'll pop back here if I find it... Alas Mama Lolly's is no more in St Johns-I think she has a stand at the university now instead.