As fas as I know, the Canaries are the only place in the world to have tour guides with an official qualification in astronomical tourism. The first batch of 14 starlight guides qualified in 2011. Most of them are based on La Palma, although there are now many guides on Tenerife too. Most nighttime star observation is led by a Starlight Guide and/or a Starlight Monitor.
Each of the new Starlight Guides has passed a course consisting of 120 hours of lectures (on astronomy, the island, and tourism theory) plus practical activities like stargazing and hikes. You can find details of the course here, (in Spanish). The courses are only available in Spanish.
Many tourists say that stargazing was the best part of their holiday.