The soprano recorder plays quite high notes, so the music is written an octave lower than it sounds. For tenor, it plays exactly the pitch which is shown on the music.
Since the notes it plays are from middle C at the lowest, the music fits nicely on the treble clef.
You can always play any treble clef soprano music - it will come out an octave lower than it would on a soprano. Ideally, you need to play the tenor part if the music is written out for several different instruments. It's also possible to play the alto parts, as the higher notes on tenor are within that range. Although it makes sense if there's an alto player, that they play the alto part, leaving a lower part for tenor. Obviously if tenor parts are lacking, double up on the alto (or even soprano) parts.