I used TransMac on Windows 7 to restore the image file I had to the Flash Drive, it created a bootable Mac image on my flash drive.
Dryden's Link, I was able to use the Diskpart command to clean and prep a GPT partition on a flash drive for an OSX Mavericks install image. I was never able to write a Mac installer image to my Flash Drive and have it bootable, unless I did it on a Mac. I know this question is old but it is still valid.