With the serial port not found on the Power Dock how do you connect to Omega?
With putty (if windows) and ssh. You need a network (wireless) connection.
Because it's just OpenWRT I think @Luciano-S is right and feel like other people have successfully used a USB to UART adapter.
As @Luciano-S and our Power Dock Guide already mentioned, you must connect to the Omega on the Power Dock wirelessly over SSH. I have updated the article with a link to the guide for connecting over SSH.
@Luciano-S : It is possible to connect the TX/RX wires from the USB to UART adapter to the Serial TX/RX pins on the Power Dock's header, but do so at your own risk. The Power Dock was intended for people to connect to it wirelessly without having to remove it from whatever it's embedded in.