The ornamental design for a portion of a bottle, as shown and described.
FIG. 1 is a top, front perspective view of a portion of a bottle depicting the new design;
FIG. 2 is a front elevational view thereof, the rear elevational view being a mirror image;
FIG. 3 is a left side elevational view thereof, the right side elevational view being a mirror image;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a bottom plan view thereof.
The dash-dot lines immediately adjacent to the shaded areas of the bottle represent unclaimed boundaries of the claimed design. The dotted lines showing the remainder of the bottle are for illustrative purposes only and form no part of the claimed design.