There are not a bunch of places serving oysters and Champagne in Tenerife, at leats not focusing on this type of serving. But there is a Champagne & Oysterbar in the city centre of Playa de Las Americas in the south of the island Tenerife; WISHES. It is quite easy to find and even if you do not reside in this touristic city you can easily enjoy yourself since there are lots of parking spaces around the city. Just know that people come there for the beaches so there might not be parking space close by to the bar around noon but later in the afternoon should be fine.
Address: Avenida las Americas 26