Does it squeek?

Then don't worry about it.

Otherwise adjust it.

  You don't the belt will run side to side even when rear wheel in in line.

As said, sprocket is mounted with rubber dampers.
But follows the adjustment of the wheel somewhat.
Mine had a little squeek after I fiddled with it trying to get it in the center.  Quarter turn this way and that and it squeeked.  Jacked the rear off the ground, spun it, adjusted the left one just a shade tighter (the belt was a little loose) belt went into the center and it stopped squeeking.  Thanked my lucky stars and haven't looked at it since.

So... unless you have some wear/squeeking/burr up somewhere... leave it be.  

No squeeking, some people should be so lucky.  

Here's a cheapie way to align the rear wheel:

It goes without saying that you can't trust the index marks on the swingarm.

I used this the compare the distance from the swingarm pivot to the middle of the rear axle on both sides of the wheel:



I got my beam compass for about five or six bucks at Sears:

http://www.sears.com/sr/javasr/product.do?cat=Hand+Tools%2C+Carpentry&pid=009...

IHTH someone!