Short answer: Yes, a bit.
If you do the licences and practice with regular road cars on stock settings, it will help you with some things, like improving response times, wheel and movement control and adquiring the correct mechanical reactions to unexpected behaviour of a car in real life, like understeer or oversteer.
That being said, this is still no reason to go out on the road to try out your "skillz", because unlike GT5, there are too many uncontrollable variables in real life driving.
So, to sum it up:
-Does it teach you how to drive a real car? No.
-Does it add knowledge about car behaviour and improve your motor skills? Yes.
-Did it help me avoid a car crash in real life? Yes, but the situation could have been avoided altogether if I wasn't careless in the first place.
-Does it allow you to go out on the road to push the car's limits and your own? Definitely not.
Bottom Line: Be content with the fact that you might have learnt something, but pray you never have to use it.
Cheers