If you connect a bt transmitter like this one http/www.avantree.com/product-bluetooth-audio-transmitter-avantree-priva-1122.html
to the phone instead of using the internal one you can pair with two speakers.
You will not get stereo but mono through each speaker. To get stereo you need a pair of speakers with one bt receiver for both. That would be able to pair with your phone directly since the phone would see it as one device.