The better schools tend to be in the more affluent areas and that is irrespective of what faith they promote.
In Wolverhampton we have St. Peters, C of E School and St. Edmunds, Roman Catholic School.
Both just off the Compton Road, and as you say, in a more 'affluent' area.
But kids are bussed in and driven in to both schools from all over the Wolverhampton area.
You don't even have to live in the Catchment area of the schools, to get your kids in there.
For people who send their kids to these kind of schools, it's a great way for them to avoid sending them to their local junior school / comprehensive school. (The kind of schools that my wife, my kids and I attended). Many parents will have genuine religious beliefs but of course there are also plenty that will pretend to have a particular religious 'calling', to enable them to send their kids to the school of their 'choice'.
I do see a lot of hypocrisy here. People like Nick Clegg declares himself to be an Atheist and then sends his son to a Catholic School that is "....one of the most prestigious and highly regarded schools secondary schools in London...."
He can 'hide' behind his wife's 'beliefs' and justify why he didn't send his son to the nearest local comprehensive school.
In true Lib Dem style, he also preaches multiculturalism, inclusiveness and, ironically, Equality !!!, whilst conveniently finding a reason not to send his son to a multicultural school. It's called "Do As I Say, Not As I Do".
He is not alone. Many, many parents up and down the country will do exactly the same thing.
It wreaks of Double Standards and Hypocrisy, under the guise of "I'm only doing what's best for my children".