Donna-
On our Vespa tour, the owner did the tour as did some employees- I tipped the EMPLOYEE. Even though the owner provided us with exceptional service and was a wonderful guide, we know that they make the bulk of the fee.
In Rome for the bike tour, I tipped the young lady who did the tour not the owners.
We also went to Bellagio and did a last minute boat tour (engagement gift to ourselves) and being that the owner and guide were one and the same, we did not tip over the price quoted.
You are correct, though, that Italy is not a tipping place, which is why I did not tip at meals since they earn a living wage. On the guides, however, I felt appreciative of the ones that took our experiences to the next level and we wanted to give them a little "extra."