Boston has always been a little tough.

Not a Boston Domme per se but San Fran based Miss Grey of mygreyheaven.com has had touring dates in Boston every month or two recently. I've never had the pleasure but she is well established and has a good reputation. In her Tweets she mentions she has access to a fully equipped dungeon in Boston so it might be worth reaching out. She is there next for 5 days starting Dec 9.

Another option might be Goddess Nemesis. Not in Boston itself (western Mass I think?) but her dungeon looks amazing. It's in an old mill and looks very Gothic......and she looks to have a VERY impressive collection of gear if that's your thing.