I bought a Trek 1420 in 1992 and my son still rides it. It's a bonded aluminum frame that's now 24 years old and has an absolute minimum of 30,000 miles and probably a lot more. So far, so good so they may eventually fail but this one hasn't.

I personally have never seen one of these Trek bonded frames fail but I've read a few accounts about those that have. It doesn't seem to be too common.