The ornamental design for a shelf for bottles, as shown and described.
FIG. 1 is a perspective view of a first embodiment 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.
Portions shown in broken lines are for illustration only and form no part of the claimed design. The dot-dash broken lines represent the bounds of the claimed design and form no part of the claimed design.