Can iTunes sync albums from two iPhoto Libraries to one iPhone?

You can't.

Photos can be transferred from one computer only and from only one iPhoto library.

The same applies when manually managing photo storage on a computer without an application. When manually managing photo storage on a computer - creating folders for select photos, etc., you can create a parent folder that will include the named folders of photos that you want transferred to your iPhone followed by selecting the parent folder under the Photos tab for your iPhone sync preferences with iTunes. If you select a different parent folder or a different folder of photos outside of the previously selected parent folder that was transferred to your iPhone, the previously transferred folders of photos in the original parent folder selected will be removed from your iPhone first.