Bluetooth works ok if you're not sharing receivers or if you don't have more than one device acting as transmitter. Anything beyond that where you're mixing and switching devices, or sharing receivers (like multiple speakers in your household etc.) it gets so easily confused.

I've even had problems following my wife's car. Despite being fully paired with my car and working great, the transmitter (phone) will keep trying to connect to hers.

It's probably one of the most frustrating mainstream technologies that you're basically forced to use as physical connections become less and less available.