Hmmm, I've never really worked a salaried position!
I work on a job by job (event by event,, show by show) freelance basis.
I set my rates, and about every 18 months, I set a new day rate.
The only equivalent, to what you describe, is, when the client is particularly happy, and gives out a bonus or tip. It's not very common. (well, it is for the lower levels of workers, but as a Production Mgr, or Production Coordinator, no) so, when it happens, it really does stand out.
RE: Unexpectedly more