not an expert but here's the guidance online I have found
"When can goods, facilities and services be provided only to people from a particular religion or belief? (no change)
Example
A training project ran a seminar for unemployed people to help them prepare their CVs. Mehmet, a Muslim delegate, wrote to complain that he was not excused from the seminar to go and observe his afternoon prayers. The next time Mehmet applied to attend the seminar, he was told that there were
no places left but he later found out that his friend had been given a place, even though he had applied later than Mehmet. Mehmet argued that this was victimisation because he had made a complaint related to his religion.
What has changed?
There is now no need for the victim to show that they have been less favourably treated than someone who has not made or supported a complaint under the Act.
In cer tain circumstances, you may be able to specify that you will provide goods, facilities or services only to people of a particular religion or belief.This will apply if your organisation exists to:
• practise, teach or advance a particular religion or belief,
• provide benefits for people who hold a particular religion or belief, or
• promote good relations between people of different faiths.
If one of these apply then you may be able to specify the religion or belief of those to whom you provide goods, services or facilities.You will have to be able to show that your services are restricted:
• because of the purpose of your organisation, or
• in order to avoid causing offence, on grounds of your organisation’s religion or belief, to followers of that religion or belief.
However, these specific rules do not apply if the sole or main purpose of your organisation is commercial.
link
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/85027/vcs-religion-belief.pdf