The ornamental design for a shelf for bottles, as shown and described.
FIG. 1 is a perspective view of the shelf for bottles showing my design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a perspective view thereof showing exemplary use thereof.
The broken line in the figure drawings represents unclaimed environment only and forms no part of the claimed design; the break lines that separate the parts of the shelf for bottles and the portion within the break lines represent indeterminate length and form no part of the claimed design.