The ornamental design for a surface configuration of a front bumper for a vehicle, as shown and described.
FIG. 1 is a front view of a surface configuration of a front bumper for a vehicle according to our novel design; and,
FIG. 2 is a right, perspective view of the surface configuration of a front bumper for a vehicle according to our novel design, the left perspective view being mirror symmetrical.
The broken lines included depict environment and are not part of the claimed design.