Can a pokemon go plus pair with multiple phones?

Solution 1:

As stated on Pokémon Go Plus Support, in order to use Pokémon Go Plus an another device, you need to unpair with the device it is currently linked to.

Troubleshooting

Unpairing Pokémon GO Plus from your device

To use the Pokémon GO Plus with another device, you’ll need to unpair the Pokémon GO Plus.

1. Press the function button. The light will flash blue, indicating that the accessory is paired.

2. Wait until the accessory has stopped blinking.

3. Press and hold the function button for 5 seconds. The indicator light will turn solid blue.

4. Release the function button.

5. While the light is solid blue, press and hold the function button for another 5 seconds. When the Pokémon GO Plus vibrates, it has been successfully unpaired from your device.