Reinforce aluminum pipe attached to wood posts in fence
Epoxy would be your best all-round bet for this type of application. It bonds reasonably well to clean PVC as well as to aluminum. It bonds extremely well to wood.

I'd have recommendations for a specific type of epoxy, but just about anything will work in your project.

The strength comes from clean surfaces. Use a light sandpaper on the aluminum, perhaps clean the PVC with acetone, even a bit of sandpaper on the wood is a good idea, blowing out the sawdust. The sanding of the aluminum provides a bit of a grip area along with getting a clean bond. 

Epoxy does not require clamping for good results. Excessive clamping forces out the epoxy reducing the bond, but you would not have an easy job clamping your project as described.