Yes, in most places tipping is expected. At your tour, ask your leader about the local custom and advice on how much is recommended there.
At the end of the trip, if your happy with the service, the gratuity- though not compulsory is appreciated. While it may not be customary to you, it’s of great significance to the people who will take care of you during the day , inspires excellent service, and is an entrenched feature of the tourism industry across many Palmvietnam destinations.
