The ornamental design for a surfaceconfiguration of a rear bumper for a vehicle, as shown and described.
FIG. 1 is a right perspective view of a surface configuration of a rear bumper for a vehicle according to my novel design;
FIG. 2 is a front view of the surface configuration of a rear bumper for a vehicle according to my novel design; and,
FIG. 3 is a right side view of the surface configuration of a rear bumper for a vehicle according to my novel design.
The broken lines are for illustrative purposes only and form no part of the claimed design. Enclosed is a set of photographs of an embodiment of the invention.