I agree with the overall summary in that article. I'm a newly ex-restaurant worker and I therefore usually tip 20% or higher, including wine service. In the rare occasion where I buy an expensive bottle off the restuarant's list (that would be over $100 in my case) then I would tip maybe 15% on the wine but will increase that amount to 20% if the waiter and/or sommelier provides excellent wine service. That would be proper presentation, pouring, refilling and, if need be, decanting. For the extra attention (mainly keeping our glasses filled) I would give extra.
The problem is, most of my experiences with restaurant wine service involve me refilling our own glasses at some point. Hey, it happens.
As for selling expensive bottles, when I waited tables at the Capital Grille here in Chicago I sold many, many bottles in the $200-600 range, and usually got between 15-20% tip on the whole check. But I do agree with the Bruni article's source who said that if the waiter received a 10-15% tip on the whole bill if it was over 60% wine, I would be fine with that as well.
I hope that helps.
- Mark
Homer: Are you saying you're never going to eat any animal again? What about bacon? Ham? Pork chops?
Lisa: Dad, those all come from the same animal.
Homer: Heh heh heh. Ooh, yeah, right, Lisa. A wonderful, magical animal.