Try an independent BMW shop if you want an alignment. But first question (just to make sure), you're sure your alignment is off?

Generally, when you get a new set of tires, you need to balance them, that's a given. But what I've learned is that 4 wheel alignments are usually done when there's something wrong, i.e pulls to the left/right, uneven wear or stuff like that. It's not a routine maintenace thing.