You are correct. If you glamour an item that only certain jobs can wear onto an item that other jobs can wear only the jobs that can wear the first item will appear with the glamour.
Wow that's a confusing sentence.
Example
Base item Daystar Robe (WHM/CNJ/SCH equipable)
Glamour item Cleric's Robe (WHM)
Result is you will see the Cleric's Robe when a WHM and the Daystar robe when a SCH.
