This London-based band was active throughout 1968 and supported visiting US soul acts. They also opened for Jethro Tull on various occasions, which is how Barre got to join the band in early 1969.
Tomlinson helped out on an Elton John BBC session in October 1968 and then moved to Montreal, Canada early the following year where he played with a host of bands, including Milkwood. He also did a brief stint with Rhinoceros in early 1971 and later recorded with Bearfoot and Rick James (pre-Motown). He made two solo albums in the late '70s. The other members of Gethsemane appear to have dropped out of the music scene.
It is uncertain whether the band recorded any material, but it is unlikely.