The ornamental design for a wall-mountable towel bar, as shown and described.
FIG. 1 is a right front perspective view of a wall-mountable towel bar in accordance with my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a right side elevational view thereof, a left side elevational view being a mirror image thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a right bottom perspective view thereof.
The broken lines in the figures are for illustrative purposes only and form no part of the claimed design.
The rear elevation view of the wall-mountable towel bar is not shown in the drawings or described in the specification and, therefore, forms no part of the claimed design.