"We will not pay any extra for wine service unless they show expertise and then not a % (I've worked in the wine trade for 30 years ) but then only around $10 regardless of the wine cost . Wine sales in restaurants are a massive profit earner so we will not pay a % on already very inflated prices .".. from my OP
My OP above may be where you got the idea I'm a Sommelier (wine waiter) I was in my student days, but for most of my career I have been teaching professional wine industry qualifications . While I have a good understanding of wine service in restaurants in Europe I cannot say the same for the USA . As for 'testing' the server - that is not what I said - I said I would be happy to tip on wine if they showed 'expertise' .
My "calculation" as is clear from the OP is a question posed to ask if it would be considered 'acceptable' and to start discussion for those reading this forum that don't know tipping is (as it appears from these posts) is not about rewarding for good service rather about paying a servers wage .
I think after fully reading all these posts it is clear to 'foreigners' that feelings run very deep regarding tipping and they will now understand its importance and that "non obligatory" is in fact " obligatory" .
In my opinion, It would be simpler and better for staff and guests to include the servers wage in the menu price rather than hide it as a tip, allowing diners to know the true price of the meal they are about to enjoy. All this may be common knowledge in the US but after a straw poll of my family and friends 9 out of 10 were not aware of the tip system in the US, none were aware that you should always tip even with poor service.
There also appears to be an air of hand-wringing, holier than thou and finger pointing over this for daring to bring up this subject for discussion . I'm sure many reading have not dared put their thoughts forward due to this, least you should be branded at best "cheap"
Disagreement surrounds the whole subject of tipping another reason I think 'tips' included would make things simpler for all, a tip would be a tip in its dictionary meaning.
Should it then follow that if a tip is in fact a wage then everyone should give more say 25 or 30% to reward good service ?