when I got my bike fitted, it was made clear that the fit was guaranteed for 6 months and that I could come back in as often as I needed to tweak it until it was perfect.

As it turns out he got it right the first time, but offered me a free fit when I got back on the bike after recovering from an accident and my position had changed somewhat.

I guess it all depends on the bike shop and fitter.
personally I bribe my bike guys with homemade goodies a couple of times a year.

marni