This is from the Beach & Yacht Club FAQ:
Can you see any of the Illuminations fireworks from places around the resort?
There are a few places where you can view some of the high fireworks from EPCOT's Illuminations show. Many people recommend watching the fireworks from the bridge between the Beach Club and the Boardwalk resort areas. You can also see some of the high fireworks from the Beach Club beach or from the Stormalong Bay pool.
From bridge between Beach Club and Boardwalk (photo by pixarmom), from the beach (photo by creativeamanda) and from Stormalong Bay (picture by natebenma):
Yes, there are certain places around the resort where you can see some of the upper Illuminations fireworks
No, the club level lounges at the Yacht and Beach are not some of those places. There actually aren't decent views from the lounges.
Yes, some rooms do have fireworks views. No view category will guarantee it though. An upper floor, Garden (woods) view, facing EPCOT is the most likely room type to be able to see Illuminations, but there are others.
I had a standard view, club level room and I could see a few fireworks from Illuminations, but I had an excellent view of the upper fireworks from the Magic Kingdom fireworks.