Technically you can hook up the Epson 3800 to a wireless router, set up is easy but there could be a lot of problem afterward. I connected my 3800 to the wifi router in the living room and tried to print via Wifi. Sometime it works but some time it doesn't. If you connect install add the printer through apple talk or Bonjour, you may find occasional communication error. The communication error won't show up if you add the printer using IP, but even it continue to print, it could be very slow, said 1 hour for a A3 print. What wasted is not only time, after I finished the prints I checked the ink consumption, you guess? a A4 took 8ml and another A3 took 22ml.
End up I do all the photoshop work on my iMac and move the file to the Macbook to print through wired network. Or as Peter suggested to lay a ethenet cable if possible.