I'm sorry that your wife had to endure that kind of ticking off. From my own experience a little common sense goes a long way. A friendly, sober lady asking for 2 bottles is very diferent from a roudy stag party asking for 2.
To be on the safe side I always made a mental note of who had asked for 2 and would not serve a third if they polished them off in the first 20 minutes and were up for thirds and fourths. I cetainly wouldn't be reading the riot act to a sober passenger and embarrasing them infront of the entire economy section!
Intrestingly I had the passenger perspective on overzealous Qantas cc who gave me the third degree on use of the overwing exit when I was on a trip from Singapore...I respect thoroughness but this woman had a manic glint in her eye as she asked me SEP intensity questions regarding when/where/how/when not to use the thing....she seemed very crestfallen when I rattled off the answers....Having said that I do like Qantas and I'm sure, like your experience, it was a rogue bad apple.