Monetary manaism is an advanced form of possessive manaism, in which mana can be transferred to other individuals. In a sense, it is a meta-mana system. As a form of manaism, monetary manaism holds that spells can be powered with mana.
Because mana can be transferred, mana thus operates as a medium of exchange and store of wealth, just like real money. This allows for concentration of mana-wealth in the hands of the few. This of course gives the rich an incentive to get as much mana as they can.
Societies where the monetary manaism faith dominates don’t rely on other mediums such as gold/silver bullion, notes, or gemstones. In some places, it is outright banned to use anything other than mana in any transaction. This in turn means the populace has no choice but to use mana to pay for things such as rent and foodstuffs and taxes, and the mana they can produce innately (as per personal manaism) would not suffice for this.
Mana can be used to transfer mana directly via verbal command (spellspeaking). The transfer process is not perfectly efficient (transaction costs), but enchantments exist that can reduce these costs (these enchantments, being made of mana, are thus only worth their cost to the relatively well off).