This game uses DirectPlay. CrossOver doesn't have its own working Dplay implementation yet, but you can use the Windows one. To do so, just install the DirectX runtime into the bottle.
There's one "bug" in DirectPlay that might cause you some headage. Dplay expects that your hostname resolves to the IP of your external network card, not the loopback interface.
So, lets assume your hostname is "foobar", and your network IP is 192.168.0.2, your /etc/hosts file needs to contain this mapping. Linux distros by default set the hostname to resolve to 127.0.0.1, which is the loopback interface. This causes dplay to bind the server to the loopback iface and search for servers there as well, which prevents it from working properly.
If you have two network cards, set the hostname to the IP of the card you want to use for the connection.