Dealing with Cleric Levels for Domains GP when your not a Cleric

[TwistedFaith]

Ok so I kinda just came across this small problem. I was looking through domains to choose as my next one and I noticed that some of the DP's are based on your cleric levels (such as the Lust domain's GP being Once per day as a free action, you gain an enhancement bonus to Charisma equal to your cleric level. The power lasts for 1 round.). So seeing as there are ways to gain domains without having any cleric levels how would this work? Would it be based off your main casting character level? or something else?

[Malphegor]

I'd personally work it as being based on the class that gave you the domain, so for example if you were that domain power variant of wizard or whatever you'd use your wizard level, but there's nothing RAW that I know of to suggest this,

and it is very possible that the RAI is that it is very limited to nothing if you are not a cleric.