Question about retainer ventures.

It says in the 2.2 pre-patch notes that you can only send your retainer out on a class your character has actually unlocked. (Like if you leveled GLA but not CNJ, you could send your retainer out as a GLA but NOT as a CNJ)...but what if you have both GLA and CNJ unlocked, but your CNJ is lower leveled than your GLA? Does your class level matter or effect your retainers class level? Does your retainer 'cap' at your current class level (like if your CNJ is level 15, will the retainer only be able to hit level 15) or is it separate? (so in theory, your Retainer could have a level 50 CNJ, and your characters CNJ is only level 15)

I'd like to know so I can plan my ventures and Retainer roles accordingly.