Any bike that has fittings for a rack would be strong enough. This would exclude any ultra-light racing bike. Hybrids have plenty of metal in the frame and have been used for touring all over the world. The wheels are often the weak part and may benefit from a tune-up by a good wheelbuilder.
If you are asking specifically about the Trek 750 FX, then I would query the use of Al for the fork. Al frames (in this part of the range) are not ultra-light and are quite strong.