Your telematics device collects data on how the car is being driven, not who is driving it.
This means that someone else driving your car would factor into your driving trends, so it’s important for any named drivers to drive carefully.
Your good driving discount at renewal is worked out from how you've driven over the whole policy year.
Remember: only named drivers are insured to drive your car. Even if someone has their own insurance, they're not covered to drive your car unless they're named on your Certificate of Motor Insurance.