I have a TP-Link EAP225. It has only one ethernet port. It's PoE. I installed OpenWrt in it.
I have an install of OpenWrt in a vm. it has the network 192.168.20.0/24
I want the eap225 to connect to the other OpenWrt and distribute the lan and internet access over wifi so other clients can connect to it and access the lan and internet.
--
I really don't see the question here (or in other words, I can imagine multiple tangents from here -ranging from router side configurations, VLANs, PoE injection, etc.-, so I really don't want to guess).
The bridged-AP wiki page works, it's being tested several times a day, every day.
Obviously you might still hit a road block, but let's revisit this topic when you have actual problem with the config files and error messages to back it up. It doesn't make sense to speculate beforehand, you could fill whole books with potential pitfalls - and you might never hit any of those hypothetical issues and/or hit something completely different. In general you can assume the wiki pages for common issues (of which bridged AP is certainly one) to work, because it's used regularly by many users.