Training by union employees is allowed in the contract. A union trainer is given a 50-cent premium for time spent training. It used to be done in my building years ago, but we have training supervisors now. Thats good to hear that union driver trainers may be spreading around. I've always considered the management training program to be a waste of money. Most of the training supervisors in my building are often doing nothing. It's obviously cheaper to occasionally pay a 50 cent premium than it is to add dedicated management trainers, whom often have nothing to do.
The original poster is speaking of actually running areas as a union employee, I think. Well, you work as directed. If you're asked to do it, then you do so. On days when we've had no supervisor, I've been told to do it, while management told the rest of the area, "Do what this guy says today." You can't be paid in any special kind of way.