For this to work you need to have SSH access enabled!

List the Inventory:

vim-cmd vmsvc/getallvms

The first column is the <vmid> needed for below commands.

Check the power state of the virtual machine:

vim-cmd vmsvc/power.getstate <vmid>

Power-on the VM:

vim-cmd vmsvc/power.on <vmid>

Reboot the VM:

vim-cmd vmsvc/power.reboot <vmid>

This command shows all available VM options:

vim-cmd vmsvc

For options on vim-cmd, just type vim-cmd or vim-cmd help:

~ # vim-cmd
Commands available under /:
hbrsvc/       internalsvc/  solo/         vmsvc/        hostsvc/      proxysvc/     vimsvc/       help