If you want to use an ANT+ sensor over Bluetooth, you can use the 4iiii Viiiiva heart rate monitor as a bridge and convert the signal. This is useful for Zwift devices that only receive a Bluetooth signal, like iOS and Apple TV.
To get your sensors to transmit through your Viiiiva, follow the instructions in your Viiiiva instruction manual on page 5.
Your Viiiiva heart rate monitor must have the default name in order for this to work with Zwift. Instructions to change your Viiiiva's name are on page 6 of the instruction manual.
i.e. 4iiii HRM should work. Jon's HRM Strap will not.