Also check the spec of the Echo BT, along with link above. My understanding is that current BT is backward compatible, so unless the Mac BT is an "ancient" version, it ought to work. How well does the Mac stream BT to your other devices? If device has a current version of BT, thus it's similar to the Echo. and it works, then I would imagine the Echo would not have an issue either.
I have a 2009 model laptop running Win 7, and BT to my devices (Echo, Dot & Tap) and current BT speakers works fine.