The latest version of Quartz Composer for Yosemite is now available for download of the Apple Developer site.
All Plug-Ins except for Kineme Data Tools appear to be working fine.
For a Yosemite compatible version of Data Tools see the pinned doc on the Facebook Quartz Composer group.
Graphics Tools for Xcode – Xcode 6.1 October 16th 2014
Direct link for Kineme Data Tools for 10.10