I happened to update my Bose SoundTouch 20 a few weeks ago.
After the update the ST20 rebooted with the WIFI indicator constantly blinking.
Now this is the strange bit:
Through the Bose app on my IPad Air 2 & Android phone, I have tried to look up for my house WIFI network and the App/Speaker is displaying all possible WIFI networks but the one of my house.
It infact is detecting WIFI networks which iPad Air 2, Android phone or Computer also are not detecting. I mostly use the ST20 via Bluetooth from all my Devices but I would like the WIFI bit also working. Moreover, the Amber WIFI light is annoying the hell out of me.
Sorry to hear about the issues you're having with setting your system back up.
Can we do a factory reset on your SoundTouch 20? Just hold the VOL- and 1 buttons on top for 10 seconds, and this will factory reset all settings on the system. Try and set it up again with either a computer or mobile device, and lets see if it can now find your Wi-Fi network.