Bushings

Bronze bushings are definitely the way to go over plastic on this application & will probably never wear out. It was, most likely, a lot cheaper to do plastic bushings than bronze & they also may have had plastic bushings of that exact size the already that the factory used for something else too, like other linkages on the auto transmission etc.
Knowing the right people, machinists for example, & having the proper tools make doing stuff like you did pretty easy & the way it should have been done. Nice job.
Replacing the steering shaft bushings with needle bearings instead of plastic is way better too & not difficult if you already have the column out.