As long as the vents were not directly above the exhaust manifold and intake filters that it shouldn't be too much issue,
There are quite a few manufacturers that include bonnet vents from factory and some of these like the Toyota Celica vent their directly above the turbo and alternator without affecting the vehicles reliability.
if the Bearings on your alternator, power steering, and air-conditioning were subjected to lot of water you may find they would wear quicker but I doubt it's going to be that obvious.