tenor is a must learn for a trombone player, I learned it and now I have to play tenor almost every orchestra piece, so for all those saying that its stupid to use it, why would all those big composers use them for repertoire that's the same range as this? So just learn it guys, you'll get big advantages
For everyone saying Tenor Clef is useless, like it or not if you want to pursue Trombone after high school it is something you should know. When I was a sophomore in high school my director made me play a solo written in tenor clef, saying that alone makes it a harder piece to play and increasing difficulty. I hated learning it and still despise Trombone parts being written in tenor clef. However, the next year I went to All-State and the 1st Trombone part was written in tenor clef, so despite not being the "best" Trombone player that year, I was the only one able to play the 1st part in the All-State band. All that to say if you are still in high school and serious about Trombone, I would highly recommend learning tenor clef as it will give you a leg up over other Trombonist and it's a great skill to know.
Tenor clef tends to be used when trombones stay above high Bb to save the use of ledger lines Although it's really to the discretion of the composer/arranger, so you may never see it or you may see it a lot it depends on the style of music you mostly play
