The class of the Bluetooth device will determine the wireless range of the device.
Most Bluetooth devices are Class 2 meaning they operate at a distance of up to 30 feet. Class 1 devices can operate at a distance of up to 300 feet.
Having two Bluetooth devices with different classes is not an issue, they will work just fine. They will however revert to the lowest class. For example, a class 1 headset and a class 2 phone will only work up to 30 feet.
Note: There are several other factors such as intereference, and positioning of the Bluetooth device that can also impact the overall operating distance of Bluetooth devices. If you are experiencing a dropped Bluetooth connection, try repositioning the devices, or moving to another location.