I had the same problem with my Bose Soundlink. In my case it got itself confused and then would not connect. After trial and error, I eventually figured out that it's related to the way it connects. There is a specific sequence of things you need to do to make it connect (otherwise it ends up in a confused state).
If it won't connect (Mac reports something like "cannot connect to audio device"), try this:
1. Hold the bluetooth button on the Bose for 3 seconds (the bluetooth icon will start flashing).
2. On the Mac, click the bluetooth icon (or go to the settings), find the soundlink and click on use as audio device. You should hear it playing.
If it isn't working (like it did for me), then the best thing is to reset both the Bose (clear it's memory) and remove the Soundlink from the bluetooth settings. Full instructions are here (under bluetooth troubleshooting):
http://worldwide.bose.com/productsupport/en_us/web/soundlink_wireless_mobile/pag e.html
Essentially:
1. Hold the bluetooth button for 10 seconds - you will hear a beep from the speaker.
2. Remove the speaker from the Mac Bluetooth settings panel
3. Hold the mute button for 10 seconds - you will see the LEDs on the speaker flash.
This resets everything to Manufacturer status (i.e. before you got it) and now you can connect normally.
It's a pain to have to do this every time - I nearly took mine back. But after trial and error, I managed to work out the right sequence of steps to get it to connect each and every time, perfectly (see the first few steps up above).
Good luck!