Ask Apple how you can increase the shared RAM size. Or ask the game designer for a solution.
PES games incorrectly detect the amount of graphics memory available on systems with integrated graphics - this is a bug in the game. Integrated graphics solutions have access to up to half of the system ram (e.g. 1.7GB on a 4GB win7 system) - reported as "Total video memory". The amount of memory that is reported as "Dedicated" on integrated graphics is actually a very small portion that is taken (aka "stolen") at boot for the driver to use for internal bookkeeping purposes. Unfortunately, the developers of PES didn't understand that and so they assume that there is only 64MB of graphics memory available.
This is apparently fixed in a recent PES 2012 patch (2.01)- see video on youtube here: http://www.youtube.com/watch?v=8Bsws-ukCT8
As far as I know no patch is available for earlier PES versions. Same bug exists in Grand Theft Auto IV. On some systems, it is possible to configure the amount of "stolen" video memory higher via BIOS settings which will satisfy PES 2009-2011 and GTA IV.