The Steam Version of VTMB appears to work with CrossOver Versions 15.x, with the "Performance Enhanced Graphics" option enabled, or disabled, in the Bottle's settings (under right-click menu).
VTMB has a max resolution of 1280x1024, and will not "stretch" unless you also select the "Use legacy X Window System" option in the game Bottle's Advanced settings, OR unless you patch the game. If your resolution is lower, or equal to, 1280x1024; this is not necessary.If you want to patch the game to allow resolutions greater than 1280x1024, you can use the "VTMB Res-Patcher utility" created by pirapira (included with the VTMB TPG Patch, or search Google) to make the game play in full HD resolution WITHOUT having to select the "Use legacy X Window System" option in the game Bottle's Advanced settings. The only thing is; the "VTMB Res-Patcher utility" will only run under Windows, so you will need access to a Windows computer in order to patch the engine.dll file.
NOTE: You do not need the full game installed on a Windows computer in order to patch the file, you only need to have a copy of the engine.dll file (which is located in the Bin folder of the game) ie:drive_c/Program\ Files/Steam/steamapps/common/vampire\ the\ masquerade\ -\ bloodlines/Bin/
NOTE: I will be adding Tips about installing complete Patches and Mods, but please be WARNED; if you go looking, the site hosting the download for the VTMB TPG Patch by tessmage contains ADULT content, which is NSFW, on the download page. To save you any potential headache; here is the direct link to the download:
http://www.tessmage.com/tpg/True_Patch_Gold_FINAL_with_Hotfix8.rar NOTE: DO NOT OVERWRITE THE vampire.exe with the one included in the Patch, it will not run if you do.
Last Tested/Updated: 2016.02.02 on a MacPro (10.10.x) CX 15.0.1