I asked on Kickstarter and Phil Bosua responded:

"When you launch the app for the first time it guides you through a simple configuration process. You enter your network password and then the device and all lights are paired."

I'd guess that initially, an ad-hoc network is created, through which the bulb can be configured with the Wi-Fi password.

I think I'd prefer the bulbs to all be Zigbee and instead drop a dongle on an ethernet port on the router.

I think they are their own network, so you don't connect them to your existing one.