You can use your heart rate via Bluetooth but be aware it is not so reliable as ANT+ so there could be potential dropouts.
Note that by pairing with Bluetooth and not ANT+ you will be able to see your heart rate numbers on a bike computer if you have one. However, you won’t be able to see the data on the screen live during the sessions, which means your coach won’t be able to see the numbers either. Also, your heart rate numbers will not be part of your post-session rider data that gets emailed to you.
Connection Issues: If you are using Bluetooth and having issues connecting, make sure nothing else is connected to Bluetooth, as it only allows one single connection. Be especially mindful of Bluetooth headphones. If they are connected, the Spivi connection via Bluetooth will NOT work.