I had the exp all in my inventory and attempted to use it to gain exp for my team none of my team received exp besides the pokemon that i used in the battle. I had originally used a level 100 gengar as the pokemon in battle, so no exp was gained at all for any of the other pokemon on my team. I then tried to use a level 93 forretress as the pokemon in battle. I check that i had not disabled leveling by mistake and still the only pokemon to receive any exp from the battle was the forretress i had used in the battle.

You need to turn the Exp. All on.