The Mac OSX compiler is, at present, only 32 bit. A 64 bit version will be included in a future release.
As for the VCL, I'm afraid you are to be disappointed. The VCL is a Windows only framework and will remain so. The VCL is hugely reliant on the architecture of Windows. For cross-platform (Windows, OSX, iOS), the new framework being shipped with XE2 is called FireMonkey. Porting a large VCL app to FireMonkey is a significant task. There have been a lot of blog articles just recently discussing FireMonkey and a bit of websearch will lead you to them. I would warn you that FireMonkey is very different from the VCL.
This is brand new technology and so expect some teething troubles. It will take time for the framework to mature and for 3rd party vendors to get fully up-to-speed with it. At the moment, you should not be expecting to ship a GUI heavy app for Mac compiled with Delphi any time soon. What you should be doing is getting hold of XE2, learning about FireMonkey and planning a strategy for porting to FireMonkey.