Its controlled by federal bankruptcy law, not by state laws. When Spirit files BK, assuming its CH7 liquidation, then the first group paid is the secured debt. Wages for employees are not paid at all until all secured creditors are paid. Wages are paid later, but have a maximum cap, so you could get anywhere from nothing to $15k (which I think the cap is now). But if you're owed $30k its not coming under any circumstance in CH7 since nothing can be paid over the cap.

There probably won't be any "leftover cash" since the assets aren't likely even worth the $2B that's owed to the bondholders.