You can use this KB for reference

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=101954...

Also It would be good to patch a single host & also you can patch at cluster level.If you are going to update your system to update releases you can have a single rollup bulletin which contains both bug fixes & security update.

If you want to patch only with security updates you can choose that option in update manger.