Don't know of any "official" guidelines, but when I was pregnant last time, we had friends fly to visit us with their 4 week old baby (delivered by Cesarean). The dad is an MD. They also flew with their toddler. They seemed to cope with it all very well. I think it would be harder on mom than baby (just the travelling), especialy with a first child! I don't think there are concerns about the air travel itself. I think you should give yourself at least a month in your "own nest" though, and not try it before that. I guess the implication here is that I'd be infinitely more worried about you, and your adjustment to first time parenthood than about the baby. They baby is resilliant and "home" to the baby at that point is in your arms and at your breast.
I wouldn't have been able to do it with my first. I was still a hormonal wreck. We had terrible nursing troubles and were using all kinds of gadgets until about 7-8 weeks (though it seemed like a year!) So nursing anywhere but home was very stressful (heck, nursing at home was stressful!) and we avoided it at all cost.
So I second the suggestion of not buying tickets early--even though getting a lower cost would be tempting.
This time, we may be flying coast to coast for a wedding when this baby is anywhere from 4-6 weeks old. However, I'm more confident about just about all aspects this time--or at least avoiding the same issues as last time. Actually, I was confident last time too, but things went a bit differently, I should say. Ah, the steep learning curve of the first child!