I was taught IPA as a compulsory part of the national English teachers training curriculum but ironically have hardly ever used it apart from in various professional interviews.
Strictly speaking, "reading" phonemc symbols have nothing to do with decent pronunciation, but the accent of the teacher does! (as well as anything that children can hear - class CDs, nursery rhymes, etc.) It's through hearing that we learn how to pronounce sounds and sound words, not through reading. Besides, children are generally so good at parroting!
On the other hand, doing phonemic symbols can vary the process like colouring or writing/copying, so why not? (particulary with a not very academic class)
ps. It might help to know your personal reasoning as well. ;-)