I think you are using the term "permanent" wrong there, and that "mundane, lasting the spell" terminology suits better, because "permanent" might be confused with a spell duration. When you have a spell duration going on, the spell just keeps happening, so for example if you have a ReMe spell with a duration to keep someone sleeping (or being loyal to your magus), they keep doing so and can't be awaken (or stop being loyal) for the duration, as opposed to spells with momentary duration which put people to sleep, where they can be naturally awaken afterwards.
You use ritual creo magic to create things that are actually mundane: you can use Conjure the Mystic Tower to create a tower, but it's not magic: if you hit your head against it Parma won't stop it, if you shake it with an earthquake it will crumble, and so on. You don's use ritual creo magic to cast actually permanent stuff: you can't use a ritual CrIg, CrAu or CrIm to create everlasting fires, storms or illusions, because the nature of fires is to burn out when they get out of fuel, of storms to go around for a while and then dissolve, and images are species that don't stand still in place. So I think no matter how much vis the magus invest on this spell: it will create a mundane loyalty to the magus, which will immediately start to fade off, probably quite fast as I assume most mundanes won't even know the casting magus they are supposed to be loyal to.
If he wants that loyalty to endure, he should put an actual duration to the spell, and the spell should last for that duration, and probably after that fade naturally. Anything else is a big can of worms.