From what I've seen, salary is dependent pretty much only on location and experience. When I say location, you can kind of think of it in two ways. Some areas of the country pay MUCH more, as PTs are needed more in those areas with higher salaries, or cost of living is higher, and also the setting in which you practice. For example, I think it's a pretty common trend for PTs in state nursing facilities to make more than PTs in outpatient clinics, even if they're in the same location geographically.
Also, "prestige" of PT programs has nothing to do with salary. You graduate and you take a test, if you pass you are licensed. Being from a "top school" does not make you any more licensed than anyone else. Additionally, the ranking system is total rubbish. Just find a program that fits you well and has you coming out with as little debt as possible.
A quick google search brought up this:
http://salarybystate.org/healthcare/physical-therapist-salary-by-state
I'm not sure of the validity of it, and different websites will tell you different things, but its at least something to get you started.
As far as experience goes, I'm sure someone else could give you a better idea how this works. From the PTs I've talked to, experience definitely plays a role but it doesn't hugely impact your salary. The only thing I have seen like this is PTs with more experience getting into management positions, where they're running a clinic and doing administrative stuff, and seeing patients much less. Those positions seem to pay a bit more.
Hope this helps! This is just some info I've gotten over time, I'm still a student and starting PT school in the summer!
*EDIT*
I just found this website and I'm sure it's more legit than that other one. I like the map on here and how you can scroll over different states to see the info.
http://www.bls.gov/oes/current/oes291123.htm