The latest is VMware-PowerCLI-5.8.0-2057893.
According to the PowerCLI manual, I think in PowerCLI, it support interoperability between vSphere PowerCLI and vCloud Director PowerCLI.
So when you install PowerCLI, there is a option whether you need install the module for vCloud Director PowerCLI (default not).
If you installed only supported the vCloud commandlets, it means maybe the other part.
There are different command groups to support different products.