The ornamental design for a bottleholder, as shown and described.
FIG. 1 is a front, left, and top perspective view of a bottle holder showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof; the right side view being identical thereto;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a front, left, and top perspective view thereof in which the intermediate boxes are rotated with respect to the top and bottom boxes, and in which the slidable lid is in an open position;
FIG. 8 is a front view thereof;
FIG. 9 is a rear view thereof;
FIG. 10 is a left side view thereof; the right side view being a mirrored copy thereof;