Just did mine too, since it was off for changing the wishbones. Not with a wire wheel though, just rags and cleaner, but it still came up nice. I cant put anything back on the car dirty. If it comes off, it gets cleaned.
It certainly doesn't corrode like steel does as the initial layer of ali oxide that naturally forms will protect the surface for the most part. However given the right conditions aluminium will corrode as the natural oxide layer can get damaged and allow some corrosion to form.
The pitting on the right of the OP's photo shows evidence of corrosion and so do the aluminium wheels on my bike (The anodisation got compromised water got under the rim tape and boom 7 years later I have pinholes in my wheels)
Cant beat a good bit of powder coating to make things look even more blingier
Either way the OP made a good job and is much prettier than my underside it needs a good scub at some point, pretty sure my under engine tray is protected by a nice layer of oil from old and now fixed oli leaks.