Well since it's for bball here is my input.
I'm 22 now, and was a pretty big into basketball when I was in high school and before. First off, Make sure you keep the rest of your body healthy, I'm 6'7 now and was about your height at 15 too.
For bench maybe some pyramids to gain power. But for me since I was a Forward/Center. I really concentrated on my legs, back, arms and chest.
Legs are the most important IMHO for a bigman. I neglected them my Sr. year and lost my oppurtunity to play college ball when I completely tore apart my ACL,MCL, and cartilidge on one of my knees. Also, your legs are a big factor for boxing out, rebounding, posting etc.... Quads and calves are great for this. Even if you are undersized you can hold off bigger people with your legs and butt.
I did mostly pyramid styles for power building and consistent bulking. My main mistake was my lapse in cardio always saying "that's what preseason is for". Do the cardio you lose some mass but gain a speed advantage.
Don't forget stretching either. being 6'4 and being able to move and bend in other ways that bigger people can't is a huge help.
Eat hearty meals. Don't skimp out on meals and rest.
As for a routine it depends on your practice schedule. Normally Summer time and Pre Season (depending if you are on traveling teams or not) I had practice 4 times a week. My shedule looked like this for working out:
Sunday: Off Day
Monday: Practice
Tuesday: Arms/Chest/Back (Incline, Bench, Preacher Curls, Hammer Curls, Pull Downs, Seated Row, Skull Crushers, Pushdowns/dips, Pullups)
Wed: Practice and Stretching
Thursday: Legs/Abs/Cardio (Medicine ball jumping, take a medicine ball hold it over your head jump with it and and try to touch it against the rim or back board, Lunges, Squats/Leg Press, Calves, Leg Extensions, Abs, Running)
Friday: Practice and Stretching
Saturday: Practice and Light Back and Arm (Pull ups, Dips, Concern. Curl, Skull crushers, seated row)
This might not work for you, and there are many different routines you can do, thats just what I did and I got some decent results, nothing great though.
As for the Body fat, I liked having a little "cushioning" from the other guy. I never measured it, I based it on my performance during practices and games. If i was getting to tired and worn out, off to the cardio i went to shed some pounds and waved some of the carbs away. Do what you feel comfortable with, and like Go Pro said don't neglect the rest of your body.
Best of luck!