Of course wine should be served at the seat and a taste offered, whilst displaying the bottle.
Unfortunately, like everything else, it’s the inconsistency that flows within BA, that means some get what should be a fairly standard first class etiquette and some do not!
Whether it is down to inexperience, lack of training, laziness of BA cabin crew, it’s unacceptable. Regardless of what passengers pay, they expect a first class service in a first class cabin. The amount of inconsistency in service really irritates me.

In F, I have been served wine in a champagne glass, the crew have elected to change my choice of white wine without telling me (perhaps thinking I can’t taste the difference between a Chablis and a Sancerre?), have had the table laid in an incorrect manner, have been called mate, sir, Mr XXXX and also none of the above. Have been told about the dine on demand and also given no choice but to dine when the crew wanted, have had to make my own bed up due to crew on their ‘meal break’ (and that’s after asking), have had the wrong meal served, have had the main course arrive before the starter, but also the main course arrive while eating the starter.

I’ve given up now. If I sense a crew member in F who cannot be arsed with their job anymore, I categorically say to the other crew member (if they’re any better) or to the CSD that I do not want to be served by inattentive and lazy crew and ask my server to be changed. The most recent occasion was on a LHR-JFK Flight recently where I was sat in 1K and my partner in 1A. My partner had a lovely server, mine was bored, lazy and couldn’t be bothered. He never introduced himself despite his colleague doing the complete opposite on the other side of the cabin.
So I asked the other crew member to look after us for the rest of the flight. I’m not wasting my time or money anymore putting up with that style of crap service by BA crew.