If your mobile provider offers a deal for Apple Music, then sign up with them, and not directly with Apple. When signing up with your mobile provider for Apple Music, you should cancel any current Apple Music subscription that you have with Apple directly. If you keep the Apple Music subscription at EE after the trial period, then you will pay the fee to the mobile provider, not to Apple directly. Both subscriptions can co-exist. It is your responsibility to cancel one of them to avoid paying double for one service.
You will need to register your mobile number for this bundled service, to link your mobile number to your Apple ID, so that Apple knows to give you access to this service without having a subscription with them directly.
How to get Apple Music - EE Services
About bundling Apple Music through mobile phone service providers - Apple Support