I am 62 years old, and work out every day, weight lifting. I had translab when I was 60, and had PT following the surgery. I am still mildly wonky 24/7 and I really don't think that it will ever change. The therapist said that my physical strength was key to keeping me on my feet, and without being strong and muscular, I would not be very steady on my feet.
Every recovery is different. Others on this forum seem to have very little balance problems. Hopefully, you will join that crowd. What ever happens, keep doing yoga. You may loose some of that perfect style, and you might stumble, and you might fall, but just keep doing it. There are times when I stumble, but I am strong enough to catch myself. I just rode my bike recently, but I like my teeth in my mouth, and decided not to ride the bike. My dentist agrees!
Balancing is done with your vestibular system, your eyes and your muscles. If you have translab, you will lose one of the two vestibular systems, and your brain is going to have to be retrained. I'm not sure doing yoga now will improve your post surgery balance very much unless you already have balance issues. If you already have balance issues your brain is already in the process of being retrained, and yoga now will be some help. Once that nerve is severed, yoga will serve you well. It requires balance and strength. Getting back into weight lifting after surgery also gave me a goal. I am very goal oriented, and that was a big benefit to me. Remember, muscle strength is one of the three systems that help balance you.
Be patient with your recovery. It is a long process. Set goals. Stick with it. You can modify your exercises when you start doing yoga following surgery. Yahoo for exercises...good stuff. Good luck!
James