With good surface prep, quality veneer, and the proper adhesive, there should be no problem attaching veneer to metal. I glued paper backed veneers to brass tubes for kaleidoscopes several years ago. I used 3M Vinyl Trim Adhesive (black instead of yellow, made much more sightly seams) and the biggest problem I had with adhesion was from the glue between the paper backing and the surface veneer, a problem from the manufacturer, but that was unusual.
Veneer is commonly used over honeycomb panels of all kinds, including aluminum, for aircraft and boat interiors. Those people really take luxury and quality seriously.