Yes and no. No need to apply the patch to resolve the Heartbleed issue. However, according to the build number DELL offers version 5.5.0c , i.e. the build without Update 1a. Maybe due to the NFS issue in Update 1!? If you want to patch the host to Update 1a you may apply patch "ESXi550-201404001" after the upgrade. I'd recommend you run esxcli with the "update" option as well as with "--dry-run" to see whether which vibs will be replaces.
André