This question was raised on another thread ( http://www.chowhound.com/topics/478176 ). Given the large number of BYO restaurants here in PA, I thought it was important enough to give it a post of its own. So my question is this -- when you bring wine to a BYO restaurant that does NOT have a liquor license, do you add an additional amount to the tip? If so, how much do you add? What is the basis for the additional amount -- that is, do you base it on the cost of the wine you've brought, the cost of the dinner tab, or something else? Does this change if there is a corkage fee? Do you use the same guidelines if you bring beer into a BYO, rather than wine? And if the restaurant DOES have a liquor license but still allows guests to bring their own wine with no corkage fee, how does that affect the tip you leave?
Let me add that I'm not asking for the rationalization for adding to the tip -- I fully understand about the extra service (opening the wine, providing stemware and chilling bucket, etc.) you receive that is provided at no extra charge. I also understand about potentially "lost" tips for waitstaff at restaurants that sell wine when guests bring in their own. What I am asking is how (whether) you adjust your tip when dining at a BYO.