First of all 6 or 7 hours for the majority of teens is not close to enough sleep. There are some people who seem to need less than average, but teens need a lot. Sleep not only helps with growth, but also with health in general. Fighting off colds, neural activity, memory, stress levels, weight, sleep is very very important. If you get by on 6 or 7, but then are spending maybe one day a week sleeping 10 or 12 or falling asleep for a nap, that is your body catching up. Although you did not mention that is happening.
Good enough, is not good enough in my opinion. You need to feel well rested. You are in your last years of growing, if you are still growing, so if you want to make the best of it, get your rest. My husband, I swear, grew a little when he was in his early 20’s.
Also, good posture can make a taller. When I went back to dance class as an adult, my clothes became too short, I measured a quarter inch taller in my 30’s. It’s not really growth, not bone growth, when someone is that old, but I believe it is something with the spine and muscles that legnthens.