Branded product bundle question

I’m planning on selling a “bundle” of two complimentary products. One product is clearly branded, the other is generic.

I’ve seen another seller doing something similar where the bundle is sold under their own brand.

Is this above board? Can I combine products from two brands into a bundle, get a UPC, go through brand registry and sell that as a product on Amazon under my own brand?

I imagine Amazon wouldn’t let me list under the brand of the branded product, and I don’t want to build up a generic listing just to get undercut.

I appreciate any insight you guys have. Thanks