really bad idea. I won't say it's impossible, but it would be very difficult/expensive. I've never seen it done. At a minimum you would end up with something like a sliding glass door, rather than a typical pocket door.
If it's not airtight, it's not soundproof. There's no way pocket doors are going to be soundproof. I suspect that you would have the same problem with french doors, along with most all interior doors. They don't seal the airspace around them.
In my old aparment I had a pocket door from my bedroom to the bathroom. Not only was it not soundproof (not a problem) It provided a "tunnel" for sound from below me to travel upstairs. That single wall took an apartment that was mostly soundproof, and destroyed any hope of sound isolation.
In my theater, I have a solid wood esterior door, with an exterior door threshold and frame, and it's _still_ the weak spot in my soundproofing.
If you are: 1. Willing to deal with _some_ sound transmission. 2. Willing to get exterior french doors. 3. Willing to do a good, tight install job.
Then I think you will be fine.
You might want to add some soundproofing to your bar area so that sound that escapes the theater won't leak from there to the rest of the house.