User blog comment:LordRimus/Ranked magic/@comment-173.25.157.91-20160902025100/@comment-29248623-20160902054545

Tier access wouldn't necessarilly mean Spell access. I mean unlocking a tier wouldn't really give you the assurance of being able to immediately/easily use a stronger spell or skill. It would likely depend on a combination of job levels, as sighted by Codered99's comment, and other prerequisites to spells or skills.