[Wine] /var/wine not owned by you

[klkblake]

In an effort to set up a system-wide wine folder, I have moved mine to /var/wine, set WINEPREFIX to /var/wine for all users, and changed the permissions for /var/wine and it's contents to root:wine rwxr-xr-x. The wine registry and the savegame directories for my games have g+w as well. I am a member of the wine group.
When I attempt to run wine, I get the error message "wine: /var/wine not owned by you". Since I have group permissions, why is it a problem that the directory is not owned by me, and what can I do about it given I need a system-wide wine folder?