I am not sure if they are owned by Disney or not, but we have been able to make reservations there. I can't remember if I had to call them directly to make the ressie or if I did it thru disney dining.
Yes, they take reservations (I have them for our upcoming special anniversary dinner in September) and you can do them through Disney dining. I read somewhere that they've been sold recently. And, correct, they are not on the dining plan.