Thought this might be of help to those who have cloned a Yosemite hard drive but are now missing the Recovery Partition.
To restore the recovery partition on a Yosemite install, you’ll need a few files from the Yosemite Installer, a script, and Apple’s Lion Recovery Updater.
Make sure you have backed up your drives before doing anything to your boot volume!
Login to the computer as an administrator.
Download the Yosemite installer from the App Store and look for "Install OS X Yosemite.app"
Right-click on Install OS X Yosemite.app and select Show Contents.
Navigate to Contents/SharedSupport. Copy the file InstallESD.dmg to your Downloads folder.
Download the Apple’s Lion Recovery Updater http://support.apple.com/kb/dl1464 - mount and copy RecoveryHDUpdate.dmg into the Downloads folder.
Download and decompress the file recovery.sh.zip from http://4unitmaths.com/recovery.sh.zip and moverecovery.sh into your Downloads folder.
Open Terminal and type the following commands: chmod +x ~/Downloads/recovery.sh (hit return) sudo ~/Downloads/recovery.sh (hit return)
The process will take a few minutes.
Shutdown and power back on, holding Option to confirm its installed. Click on it to make sure it boots.
I'd like to give credit to the individual who posted the original instructions at: forums.macrumors.com/showthread.php?t=1756752.