You will have to buy a copy of FTM Mac 2 and install it on your Mac Air. There is no such program as "FTM 2012 for Mac".
To transfer files between FTM 2012 and FTM Mac 2 you can either use GEDCOM which does not support media,
Install the File Migration Utility (which comes on your FTM Mac 2 CD, or can be downloaded see http://ftm.custhelp.com/app/answers/detail/a_id/5313/kw/File...
on your PC. It will not install on your Mac Air.
To transfer files you would convert a copy of your FTM 2012 file to FTMMac 2 format with the FMU and then using a USB memory stick or CD etc, transfer the file to your Mac Air and open it in FTM for Mac 2
When you come back from your trip, you would take a copy of your FTM Mac 2 file to your PC, convert it and then open it in FTM 2012
There is a partial option of creating a online Ancestry Member Tree (AMT) from FTM 2012 and sync it.
You could then view the AMT via the internet from your Mac Air
You should also be able to give yourself editing rights to your AMT so that you can manipulate the AMT online when you travel
When you get back home you sync the AMT back to your FTM 2012 file.
I would test this all before you leave.
A great future enhancement would be for the file structures of FTM for Windows and FTM for Mac to be the same and interchangeable like we can with PDF, JPG, TIF, Doc, DocX et, etc, and then we could mor readily exchange files between the two platforms.
I use an iMac with Parallels 7 and Windows 7 Pro and have both FTM versions on my computer, and can switch between them but I still need to do a file conversion.