Yep, this set up is very common, you might want to look at the plumbing forum as there are many posts on this topic already, or even do a search on google for hot water circulating systems to see how others have set up their similar systems. Other options would include a second water heater closer to the far bathroom, but that is another story all together.

chief

Constant re-circulation of the hot will create a substantial heat loss from the hot water pipe along it's length. To reduce the energy needed to keep the loop hot, you can put the recirculating pump on a timer to operate say only in the morning and even when you usually use the water, or better yet, on a switch in the bathroom that you could turn on and off when needed.

It'd be much easier to install a point of service electric hot water heater. It would effectively run ONLY to heat the initial cold water in the pipes, then shut off as hot water reached it. If you're paying for install labor (both ways), it could be less expensive than plumbing the additional pipe that you're considering.

Of course a point of use heater will probably need a new circuit...
And they also tend to scale up.