This seems to be becoming a more common thing.
The only one in my area that I KNOW does it is the Bell on Forest Road.
I checked CAMRA.ORG and there is an online form there that pubs can use after which they will be sent promotional material. As there is no indication of the discount at all in the Bell, I assume they don't have the promotional material. CAMRA.ORG claim that a database is being set up and will be available soon. I do know a bit about this sort of thing and setting up an indexed list of names and addresses is probably one of the easiest possible things to do. As it's CAMRA I'll give them two years to get it up and running.

I was talking to someone last night who told me that the new Crooked Billet in E5 would be doing discount along with a list of others, but I didnt have a pen and I was too addled to remember them all!

What I do recall was that two of the three local Antic Pubs were going to do it and astonishingly the Golden Grove Spoons down in E15, which is the only East London Spoons outside of the City area that I haven't actually been to in the last few years. If I go there I won't take the CAMRA tickets as using both would not be allowed.

I gather the new Wenlock does the discount so at the moment there are just two that I know definitely do it.

If people can post the pubs that they know DEFINITELY do a CAMRA discount then I can create a database that I can post summaries onto this thread in a similar fashion to the GB & U IPAs thread.