The L1 Pro 16's have integrated Bluetooth receivers, so if your device supports simultaneous connections, yes.
However, to run them in stereo, your mixer's transmitter must be able to pair to two separate devices and send only the left channel to one paired device and the right channel to another paired device. There may be one out there, but I don't know of one. Of course, you could purchase two transmitters, attach them to your left and right mixer outputs, and pair one to each L1 Pro 16. I've never tried this so I can't recommend any brands or comment on how successful that would be.
Some speaker brands provide this capability with a mobile phone app, when using the phone as your music source (e.g., the Bose S1 Pro with the Bose Connect app, JBL "Flip" with the JBL Connect app, etc.)
The L1 Mix app for the L1 Pro series lets you adjust the mixer settings remotely from your iPhone or Android device, but is not designed to be a music source.
The L1 Pro16 can be connected to any Bluetooth compatible device for audio streaming when placed in pairing mode (see page 9 for instructions on this). The L1 Mix app is not necessary for music playback via Bluetooth.
I understand what the mix app is for and that isn't the problem. I am able to connect my iphone to the mix app but I have not been able to connect for streaming audio. I have tried you suggestion as listed in the manual and have not been successful. I will try once more.
NOTE: I took your advice and made an attempt to contact Bose support as well as sales about the issues and questions I have 4 days ago and so far I have not received a response. Very dissapointed!