Teleport is much more about aesthetics and getting into the game than about practical usefulness. I pretty much always have a Black Wizard/Time Mage combo character, and he will have Teleport for most of the game. One of my fondest memories of FFT is Teleporting literally across the entire map to blow up a bunch of baddies to finish a fight. It is the only time a Teleport that far has actually worked for me, and it was awesome.