In a word, don't. I stopped by for a bite on my way to the BofA Pavillion. It had been years, but I had enjoyed some surprisingly decent meals in the dining room. I grabbed a seat at the bar hoping for a nice piece of fish, but the bar menu is limited to bar-like food. It did, however, include a lobster club sandwich, so I ordered that. And since it was served with chips -- lobster rolls and related sandwiches are supposed to come with fries, not chips -- I ordered their BBQ spiced fries with jalapeno ketchup.
The lobster club sucked. First, it was ice cold. Everything, including the bacon and the roll, which had the appearance of having been toasted, was ice cold. So either the sandwich was pre-made and stuck in the fridge, or the lobster salad, lettuce and tomato were kept in a fridge so cold that it made the entire sandwich feel ice cold. Second, the lobster salad was the type that looked like it was put in a blender set to pulverize. The largest chunks were ... well, actually there were no chunks. And although there was not enough filling to warrant it, it was served as a tripple decker, so had a huge amount of roll. (I deconstructed it to eliminate the middle piece of bread.) It was just a lousy sandwich. After finishing half and taking a couple of bites of the second half, and realizing that the sandwich was getting no better, I just put it down. I don't recall EVER not finishing a lobster sandwich before.
The fries were fine. They were coated with a salt-based seasoning of a sort similar to what you find on bbq potato chips and served with a too-small ramekin of slightly spicy ketchup.
On the plus side, they do have a decent beer selection, and it's a comfortable lounge.
If you make the mistake of going, note that a 15% service charge is added to all checks in the lounge. Is it that way in the dining room too? Although I dislike the practice of an automatic service charge, I applaud that they set it at the low end (15%), not the 18-20% you see at some other places (although I cannot think of other places in Boston that do this, except for larger parties).