Yes, you can connect your mobile phone to you conference phone via Bluetooth and enable the Media audio feature to allow music to be played through your conference phone.
Once you have connected your mobile phone via Bluetooth, follow these steps to enable the media audio feature:
For CP920 and CP930W:
Menu → Settings → Basic Settings → Bluetooth → Paired Bluetooth Devic →
Option → Detail → Channel Control → Media Audio.
Bluetooth → Bluetooth (On) → → Media audio.