When we booked Insight and Trafalgar, we had those automatically included, (like cruising here.). When we were finished up in Canada insight, the envelopes still got passed around as most hadn't paid the expected tips. So, if it's part of the fare I think it should always be included
I wrote on the front that we already paid those (hundreds of dollars each for host and driver), and as the tour manager was less than average I didn't want to leave extra....we still felt guilty for no good reason.
It's always a topic that makes me uncertain , uncomfortable and the system is unfair for the workers.