I was there yesterday. Perrier and, yes, Yellowtail were available and sandwiches as well. The Club side in particular got crowded towards 5pm, the F part not quite so much. Tarmac views are quite reasonable, and the lounge attendants yesterday forthcoming and friendly.
For anyone used to QF F lounge in SYD, BA's DFW lounge is obviously nothing special. Just try both and see yourself.