Both are still going strong, if you like that sort of thing. The musical styles aren't joined at the hip, but they certainly travel in the same circles. Most people had their only experience with these genre's in the early- to mid- 1990's:
Enigma had a second hit with Return To Innocence, but the song above, Sadeness, sticks with most people because it, or some variation, was used for 10,000 movie sex scenes.
Adiemus was used for a number of tv and radio advertisements for a number of years. Adiemus was the first song from the Adiemus album by composer Karl Jenkins. None of the other songs from the album were hits in the U.S. Nor where any of the songs on the SIX sequel albums.
Enigma, or more formally, The Enigma Project, has released six follow-up albums as well. Enigma could be said to have experienced more success, as several Enigma songs have featured in various movies and television shows. However, the creator of Enigma, Michael Cretu, has also been sued repeatedly for not acknowledging or paying the sources of several of the musical samples he has used.