This might be a little unrelated, but if you have trouble making the bends cleanly & in tune (not too high or too low), a good exercise is practicing two-string "oblique" bends...where you play the note you're trying to bend up to on the next string while you perform the bend itself.

When you do these, you can hear exactly what pitch you're bending up to, so it's easier to hear how to keep them in tune.

Here's an article with additional info:

http://www.guitarplayer.com/article/get-a-grip/Mar-05/4332