Retirement plan contributions and housing allowance

[Tinman]

I will preface this post with stating I know very little about church plans and how they operate - however, I've received a question and hope someone out there can help.

One of our advisors is trying to set up a church plan and was asked - if the pastors are receiving contributions in this plan, does it cause any issue with the "tax-free" status of their housing allowance?

Thanks, in advance, for any guidance!