I have noticed that the text on a lot of sites looks bolder on Safari.
Read this thread:
http://www.webmasterworld.com/css/3614559.htm
Sounds like a rendering issue possibly at a particular screen resolution. Perhaps even involving a mismatch between the monitor native resolution and the selected graphics screen resolution.
Obviously you are targetting the film industry with your site and have rightly expected visits by more Macs than most sites encounter. However you may find the problem is limited to particular hardware running the Windows version which won't be your target audience. I would check it out on a Mac running OSX before I got too worried.
You probably don't need to be too concerned about how it looks in Safari anyway. Those who use it are likely to be accustomed to the different appearance on their computer. I guess you just need to allow enough room to accomodate the chunky font.
Personally I am not all that impressed with the Safari browser. However I have only used it on Windows.
The Safari for Windows download is 19MB compared to Firefox's 7MB . This shouts code-bloat to me. It was written for the Mac and I expect it didn't translate well to Windows. Maybe it even runs inside a mini emulator.
However the new Google browser, Chrome is based on Safari so maybe the situation will improve with a bigger Windows base. The site I manage is just beginning to see significant visits by Chrome in the past month.