The CONNECT is designed specifically to integrate with an external amplifier/receiver, and bring Sonos functionality to a third party system. If you have existing wired speakers that are not currently driven by amplifier, you can use a CONNECT:AMP to bring Sonos functionality to your speakers.
Do you still need a bridge for Sonos?
This software, v5.1 of the Controller app, is now ready. this means Sonos players – specifically Play:1 Play:3, Play:5 and Playbar – can connect by standard Wi-Fi with no need for an initial wired Bridge connection to the wireless router at all.