WOW!! I am surprised of all the "bashing" over this post. To me, and maybe its only me, when someone puts a post on hear they are looking for a second opinion 99% of the time. I doubt that there are people on here that are looking for someone to TELL them what to do, and how to hunt. Everyone has there own ways. They wont work for everyone. I think that 99.9% of the people on here are good ethical hunters or you wouldn't be on here anymore. IMO, people on here wouldn't put up with unethical hunters and they would leave.
I think you, and only you, can determine if he is ready to bow hunt. Your the only one that can SEE his progress. If you think he can, or is ready to bow hunt this year, then let him hunt. If YOU don't feel he is ready, I'm sure he will understand. After all, you still let him gun hunt on your property, so he cant be all bad. I'm not trying to step on any toes. It's just my opinion, thats all.