Civilization V is now on the Linux platform and it looks like users are quite happy with the port, but it seems that the fact that a Mac OS X port was already in place played a big role.
The porting process for Civilization V was done by Aspyr Media, a company that specializes in this kind of work. Making games run on Linux is a first for them, because the developers usually bring titles to Mac OS X from Windows or they are adapting consoles games for Windows.