Whilst the Microsoft Surface Pro can be used wirelessly (as its handheld), it will need to have a display cable (either VGA/HDMI) to display to the ActivPanel. Unless you have an ActivConnect G-Series device which you can mirror your Surface Pro 4 display to the ActivConnect G-Series using the ActivCast application, although you won’t be able to interact with the ActivPanel using touch.
You would also need to have the USB cable connected to Surface Pro to allow for interaction on the ActivPanel if you chose to display to this with the display cable connected.
I am able to connect my Surface using a Microsoft Surface Connect in the HDMI 2 or 1 and then using the connect feature on my Surface. I can then move around the room and write on my Surface and students can see the work on the panel.