Hi Peter-
If you first add displacement to geometry and then create a Curvature node in the MatGraph, and use the "C" color preview, you'll see that the Curvature texture is respecting the displacement. So, you could use the Curvature node as "Bump Height" for your bump texture. For more precise control of the bump height, you could run the Curvature through a Color To Number node.
Cheers,
Eric