In order to stream music from Pandora, currently you'll need to use AirPlay with the native Pandora app.
If you are using an iOS device, music can be streamed to multiple Cobblestones by first setting up Multi-Room and then using AirPlay to stream. To set up Multi-Room, go to the Device List in the Muzo app and press and hold the device icon and drag it towards the other device to pair the devices (Please refer to attached screenshot). The two Cobblestones are now set up in multi mode.
Note that in the screenshot, the Bedroom Cobblestone becomes the master Cobblestone which will control music playback. When setting up AirPlay, the Cobblestones will no longer be listed as two separate devices, but only the master Bedroom Cobblestone will display. Be sure to select this device before starting music playback from the Pandora app. If needed, close the app and restart it so that it can refresh and only the Bedroom Cobblestone will display.
If you are using iTunes AirPlay on Mac or PC, you can stream music to multiple Cobblestones by directly selecting multiple outputs. There is no need to set up the Cobblestones in Multi Mode first.