I would think that any university that gives a degree in archaeology would be adequate. Ie.: a degree is a degree is a degree. Unless there's some bad reputation a particular single university has ?
Here's a thought: If you do a google search on all the currently active highly acclaimed archies . Eg.: those who are getting published works, hired to do digs in sacred spots, etc... Then compare where their degrees came from. If you see a trend where a bunch of them are graduates of "such & such", then ... you'd have your answer as to the most reputable, I suppose.
As for the "best way to break into treasure hunting", I think you are going to come up against resistance, if you think an archaeology degree is the way to do it. They *bristle* at the thought of Treasure hunting. About the only reason I can think that there'd be a benefit to holding a degree, is so that you can be a "fox guarding the hen-house". Perhaps it would give you credentials to get in and detect off-limits sites.
I know of one archaeologist who detected and bottle dug his sites (off-hours, when the other archies weren't around). So as you can see, even HE had to be a little ... uh ... "discreet". So gee, if that's the recipe, then why go to all the trouble of getting a degree. I can be "discreet" too, eh ?
But I think this is a waste of time. Just get a detector, and you'll find no shortage of sites to detect at. Don't need a degree.