20% is the norm. Not the new norm (In the US).
Why is 15% OK on a 'large bill for only 3 people'?
And for those who think you do not need to tip 20% on expensive bottles of wine: Waiters and Waitresses need to 'tip out' all of the staff that assist and support them throughout their shift. All of these assistants (food runners / expediters, busboys, host staff, service bartender) know what your gross sales were for the evening, and the assumption is that you earned more or less 20% of that number in tips.
They get their share of that number as a part of the waitpersons 'tip out'.
If the waitperson consistently says 'I got stiffed by my customers', the assistants either assume they are lying, or an awful waitperson.
Either way, the waitperson gets less enthusiastic support from the team when they don't tip out on their full gross, which makes their ability to serve their customers more difficult.
Which makes our experience as customers less enjoyable.
So, tip well!
