As mentioned by "Builder" and "Gazim", there are different grades of hoses. Vacuum hose should NEVER be use in the fuel system. Most auto parts stores will have both "fuel hose" and "alcohol resistant fuel hose". Expect the alcohol resistant stuff to last longer, but ethanol will attack this as well.
The most difficult problem we deal with here at the shop is the changing properties of fuel, especially the ethanol.
I would suggest changing ALL of the flexible hose (no, I do NOT sell fuel line) in your fuel system every three years. Shouldn't be that much of a problem, as the only non-metal fuel lines you should have are small connectors (flex joints) between metal lines.
Jon.
