I know a provisioning profile is created to be used with one certificate and, as I understand it, it can only be used with that one (an one specific id).
My question is if the opposite is also true. If I have a certificate, can that certificate only be used with that profile? If I create another profile for that certificate, it will be valid? Do I need to create another certificate?
It is a one to many relationship. A certificate can have many provisioning profiles associated with it but a single provisioning profile can only be associated with 1 certificate.
So essentially no you will not need to create a new certificate when you create a new provisioning profile.
However you will need to create a new certificate every year as the certificates do expire.