Do you he to be a neighbour to use the Revolution/Counter-Revolution CB - as Poland I want to attack Riga (Monastic State), but don't border it yet, but only want take the idea at this point if I can use the CB
Yes you need a border with the target country.
Moreover, I am pretty sure it will never allow you to attack a monastic state. It will allow a republic (with some exceptions, e.g, Dutch Republic cannot use it or be attacked by it) to attack a monarchy (again, with some exceptions) and vice versa, but Theocracies don't figure into it at all.
In a nutshell, it does not work for Theocracies and all special Monarchies/Republics.