There's also the "exec" keyword that lets you run a command in a "Match" block like so:

  Match host my-pc.local exec "wakeonlan -i 192.168.178.255 11:22:33:44:55:66"

This doesn't cover the case when the connecting machine is in another network but it does avoid a hop. Perhaps you could also run another SSH command in the exec condition that connects to the Pi and has it send the WoL packet.