http://bugs.winehq.org/show_bug.cgi?id=35361
--- Comment #18 from Sebastian Loncar sebastian.loncar@gmail.com --- When using the native dll of an existing windows installation, the in-game steam community will work, too.
I've wrote down the possible solutions in my blog: http://blog.en.edaro.net/2014/02/Wine-and-the-Steam-Community.html