I claim the ornamental design for a bottle system, as shown and described.
FIG. 1 is an upper perspective view of a bottle system;
FIG. 2 is a lower perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design. The shade lines shown represent surface shading and not surface ornamentation, color, or material type. The dot-dashed boundary lines shown do not form part of the claimed design. The bounds of the claimed design are defined with dot-dashed boundary lines when the boundary does not exist in reality in the article embodying the design. The claimed design extends to the boundary but does not include the boundary.