Depictions of Skeletons are not banned in China. Part of the reason that in some cases Skeletons (in the form of the Undead) are removed is that they, just like Ghosts are seen as unlucky so media companies just don't include them very often as they may reduce popularity and thus sales.
Banned sites include YouTube (from March 2009), Facebook (from July 2009), Google services (including Search, Google+, Maps, Docs, Drive, Sites, and Picasa), Twitter, Dropbox, Foursquare, and Flickr.