No, the 2FA is not tied to a mobile number. The way it works is you install the application on your phone, set a 6-8 digit numerical password for your app and then through your bank, you bind the application on that specific phone to your identity. Hence when you want to login to something you authorise with the application and your password, which means in order to auth you have to have both the phone and your password for the identity in order to verify that it's you.

I am aware of the security flaws of SMS and i realise i was unclear about the process of this in the parent comment.