Sounds like your son's tennis and academic career are more important to you than they are to him.
If tennis and being recruited by a better college were important to him, he'd be making the grades necessary to achieve that goal.
Given that he's so angry with you, might flunking be the absolute best way to rebel against you, to cause you grief. If indeed he every really enjoyed tennis and wasn't pressured to perform.
Might try not not caring. Allow him to fail and repeat a grade if need be. Could you do that? It's a risk.
In the meantime it could be profoundly useful to let him vent his anger to you and to your partner seperately, if your partner's game. Surely you know under all that anger is a ton of sadness, disappointment, grief, fear, confusion. Removing the stimulus (partner) is not going to fix him. He still has to deal with reality in the 'real world'.... not a bubble.
And if you think that any wilderness or tbs is going to help him sort out his feelings about the divorce and your new partner... best think again. My son was at HLA against my wishes and everytime he started to talk about his stepmom he was corrected or punished for manipulating. How do you work on things you're forbidden to talk about? He hated her no less when he returned, he was simply conditioned through 24/7 punishment to keep his damn thoughts to himself, no one wants to hear the bitchin and moanin. When in fact, he had legitimate complaints. HLA didn't heal that relationship. They knew they couldn't. It's why they recommended he attend a traditional boarding school, post program. My son may never regain the emotional openess and security he possessed before they modified his behavior.
If you'd rather not hear his anger and would prefer he turn it in on himself, send him to a TBS. That's absolutely what they're best at.
Many parents who seek residential placements and BM, micro manage their kid's lives. I don't know if you are, but there are some red flags. You might benefit from some Functional Family Therapy for yourself to change the dynamics in your relationship with your son. Teens don't want to be manipulated by their parent's fears. If you want to be useful or effective helping him determine what's important to him, you need to take a different tact, one not motivated by fear.
Your psych wasn't worth his salt. This could've/should've been resolved before your partner moved in. If there was an impasse, then perhaps the best thing for everyone would've been for you and your partner to delay gratification for two years until your son went to college. It's still an option. But, if he's angry for things other than you moving your partner in without his input, then his situation and the dynamics will not change until the anger is vented and the other feelings are addressed.
I would suggest that you research the methods used by any program and discuss them in detail with a professional before you make the decision to send him away. Find out enough about the day-to-day treatment as possible in order to determine if its ethical and evidence-based. Avoid industry white papers that claim programs use methods that are evidence based. If you desire more information I'm happy to compile a list for you to read.
And as others recommended, read the HLA forum. There's ample information there re HLA and Ridge Creek, specifically.
Can you elborate on this comment:
He tries his best to get my son to see the light.
Define "the light".
