It's actually kind of contentious within the apple union movement that they used the Machinists Union. Most store are talking with the Communication Workers of America, and the long long long term goal is for each store to organize under the same union so we can all eventually exist under the same one together.
And I sincerely and fervently wish everyone the best. I've known sheet metal union guys, art director union guys, camera union guys, grocery worker union guys and electrician union guys and the local makes more of a difference than the national and the environment makes as much difference as the local it seems. I have absolutely no idea what union would serve Apple employees the best and trust that Apple employees are doing their due diligence.