Important notes: you need paid timed-tickets into Longwood Gardens to dine at 1906; and make reservations in advance especially during the holiday season.
The food and drinks were excellent and the waitstaff was great. We had the Christmas prixe. I had the mushroom soup (not too many mushrooms in it), jailhouse island salmon (lovely presentation), and the chocolate tart (so yummy!).
When I was making the reservations it had asked what was the reason for the visit and I had checked off anniversary. I didn't expect our waitress to greet us "happy anniversary", or to give us a card wishing us both well and signed by their waitstaff, and for our dessert to have a "happy anniversary" sign. Loved the thoughtfulness and attention to detail they took to make our experience memorable.