'Twas the same in 80s Germany. Spent two and a half years putting many Deutchmarks across the counter at the HannenFass in Gutersloh, only to be told one evening "We do not serve the British here anymore" (not just the military note, but 'The British' in their entirety). Most dischuffed.
As for not drinking on duty, cobblers! It wasn't so very long ago that all the Snecks and Os used to toddle off to their respective messes for a stiff couple at lunchtime.
What the rules are now though, I'm not sure. However, in these days when Commanders are paranoid about their careers being tarnished by one of their troops being photographed, by our responsible and civic minded press, actually drinking some alcohol (perish the thought), I wouldn't be surprised if there is a ban on being in a pub in uniform (there certainly is with some companies in civvy strasse).
