I think once they build a relationship with a client the can be more so. First they need to know the client and their needs. One example with my current T she was born, raised and actively Catholic. She doesn't tell clients. Not because she is a ashamed of it but she knows that some of the groups of people she really enjoys working with with automatically overlook her because they would judge her beliefs. She works with a lot of LGBTQ as well as Muslims. She is the most accepting non judgemental person zi know.
With me, though. In my first appointment I told her about my Catolic faith. She said since I told her that she felt it was appropriate to bvb v fmdusclose her faith. We have discussed religion numerous tines.