I don't think it's a "dedicated" bus gate, as it looked like it had another aircraft attached to it, but gate B42 was used as a bus gate on my BA173 flight to JFK on the 21st. Our aircraft was on stand 572 - out past T5C just next to the fire station. Didn't really understand why they would get passengers to go all the way out to T5B and then bus them over, as it led to a somewhat shambolic boarding process thanks to the mixture of pax on the busses.