If you have serious issues of playing music from your Macbook Pro through Bose bluetooth portable speakers, you may try the following and see if the issue is fixed. I fixed mine which lasted over one month.
Restart the sound controller
Go to Applications>Utilities and double-click on Activity Monitor to launch it.
In the search bar, type 'coreaudiod’ to locate the Core Audio controller.
Click on coreaudiod, then click ‘X’ in the tool bar to quit it.