I will have to double check on my next visit over there (soonish), but last time I was told that for BA (in J to LHR) the lounge to use is the Almost@Home one. Maybe they didn't spot my OW Sapphire on the ticket... The whole thing is rather a mess since there is practically no information on the either of the lounges (or then I'm not that good at searching ).

I can confirm that there were only paid drinks available at the Via lounge bar the last time around (in early November). There was still the normal two bottled reds and two whites with a red/white on tap along the beer. These were free as usual.

I found the Almost@Home lounge to be quite small and somewhat too homie for my taste. There was sparkling/red/white wine on offer and a beer on tap. On a plus side there was a decent salad bar and some meat stew to be had as well.