We gave ds1's bus driver a present, like your bus driver he really went out of his way to make things easier for us.
We gave him alcohol too (cliche, but what else do you buy a gruff middle aged man) - we actually spent more on him than we did on the class teachers. This was not because they weren't good (one particularly was fantastic) but more to do with the fact that we felt that he'd gone well beyond what was expected of him.
Presents should be more like this - a genuine thank you to those you feel have particularly made a difference.
I think that's a really nice thing to do. At my DD's old school, there were so many unsung heroes/heroines who were so excellent with the children and never really received any recognition. Often people like that are so great with children even though it's not really their job to be.