Need to know before I run the update. System requirements for the standalone EFI updater are 10.8.5 and 10.9.5. I have 10.6.8, 10.8.5, 10.9.5 and Yosemite (10.10.2) installed on my Mac Pro. What, if anything, happens to the 10.6.8 drives in the system if the EFI update is installed?
Mac Pro, Mac OS X (10.6.8), 3.2 GHz Quad-Core, 24GB RAM
According to Apple's firmware update page, Macs which have a firmware update usually get them installed along with an OS upgrade or update. If not, it should appear in the App Store under the Updates tab as a separate item.
Looking at the page you linked: seems as if the latest update may be just for the 2013 Mac Pros. I'm not in a hurry to update the Yosemite drive, which is just for testing, so I'll hold off a while to be on the safe side.
Is 2015 EFI update included in latest Yosemite update?
