The ornamental design for a holder for winebottles, as shown and described.
FIG. 1 is a perspective view of a holder for wine bottles showing my new design, wherein the handle is in the disengaged position;
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, the right side view being identical;
FIG. 7 is a perspective view thereof, wherein the handle is in the engaged position; and,
FIG. 8 is a perspective view thereof, wherein the broken lines showing portions of a holder for wine bottles depict environment and form no part of the claimed design.