What size of pieces? Anything in the waist, or just the convex areas?
It's surprisingly easy to use a router on a convex surface. Since inlay routing requires such slow and careful movement anyway, there's plenty of time to adjust your tilt to stay perpendicular to the surface if you're doing large pieces that need to wrap around. Or if you're working with small pieces, then choose a center point, get the router perpendicular, and hold it at the same angle even when you move, to create a flat bottomed pocket for each piece.
With large wrap-around pieces, you'll either need to start with thick wood and sand them to fit the curve of the pocket bottom, or use very shallow pockets and sliced veneers, which flex easily.
If you're doing stuff in the waist... good luck
Perhaps it really would be best to inlay before bending then. I'd be nervous pressing the inlay onto the pipe, but being a compression bend, it probably wouldn't lose any pieces.If you want to see some really crazy curved surface work, check out the stuff Kevin Pederson does on his necks http://www.acousticguitarforum.com/forums/showthread.php?t=284337&page=17
Router work wouldn't be quite so easy on a curve that tight...
