i believe he does keep it..im not sure..check serebii.net to see.
That sucks.I think team rocket could really get somewhere if they took growlie along with them and trained/evolved it but you cant win them all.Yeah he sort of did.
I remember what happened at the end. He basically tells it to stay at his family mansion and look after his parents. So he does technically still own it and it's legally the property of James, but he doesn't take it along to battle the twerps because he probably doesn't want to see it get beat up.