Yes, Ring Smart Lights can work without a Bridge. However, without a Bridge they will not connect to the Ring app, which changes functionality and customization. Below are the two possible scenarios of how they will work without a Bridge:
Never connected to a Bridge - Smart Lights that are never paired with a Bridge will only have the factory settings, which can only be updated once they are connected to a Bridge. These devices will not be optimized with continual updates, and their settings can’t be changed. Meaning you will not have all the customization that you get by using the Bridge to connect them to the Ring app, i.e., the ability to adjust the Smart Lights sensitivity and connect to other Ring devices.
Bridge goes offline - Ring Smart Lights that are paired to a Bridge that go offline will continue to work as if that Bridge is online, except that they can’t receive updates, their settings can’t be updated, and they won’t generate Ring app notifications. However, they will still detect motion and even turn on together in a group. Meaning if you experience a power outage, your battery and solar powered Smart Lights will continue to follow their set commands. Once the Bridge comes back online (wifi or power is restored), the system will resume full operation as normal.