The ornamental design for a bottle accessory, as shown and described.
FIG. 1 is a top perspective view of a bottle accessory showing our design.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a rear elevation view thereof.
FIG. 4 is a right side elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The claimed ornamental design is shown in solid lines. The evenly dashed broken lines in the drawings illustrate the portions of the design that form no part of the claim. The dot-dot-dash broken lines in the drawings define the bounds of the claim and form no part thereof.