I was there in October and I believe they sell at least beer and wine in Emack & Bolio's, the coffee shop/ice cream shop/marketplace on the ground level near the exit to the pool area. I can't recall if they sell "liquor" but they very well may. I would call the hotel and ask to be transferred to Emack & Bolio's and ask what they have.
Here's a description from the hotel web page, but it doesn't answer your question:
A true Boston experience, Emack & Bolios serves award-winning ice cream, sorbets and frozen yogurts. This ice cream parlor is the perfect way to cool off on a hot day. Only the finest ingredients are used to create eclectic flavors such as:
- 'Bye Bye Miss American Mud Pie
- Deep Purple Cow
- Jumping Jack Grasshopper Pie
Discriminating coffee drinkers can enjoy an authentic Starbucks latte, cappuccino or Frappuccino®. Candy, snacks and drinks are also available in the Marketplace.