Difference between ground cloves and clove powder?
No, spices are commonly sold as "X powder" or "ground X". As far as I can tell, they are likely the same thing. The only thing I might imagine would be different would be the size of the grind.

I would imagine yes, you can substitute one for the other.

eg:
http://www.livestrong.com/article/497275-cinnamon-powder-vs-ground-cinnamon/