Guest WiFi and bridged ports

My setup: router LAN (192.168.1.x) ---> (eth1) AP LAN WiFi (dhcp from main router) + a Guest Wifi (192.168.2.x with dhcp on the AP + firewall config)
My question is if I want to connect a PC to my LAN subnet (192.168.1.x) on a port from the AP lets say eth2, do I have to bridge ports eth1 and eth2 on br-lan ?
Thanks

If I get things correctly, you have connected through an ethernet cable & configured a sub-router as an AP (no WAN). The guest Wifi has its own interface definition with firewall rules & dhcp. Assuming this is right and that your AP router has vlan capability, connecting a PC to a LAN port should establish a layer 2 connection to the main router meaning it would act as a dumb switch (pure extension) with no routing involved. Therefore you don't need to do anything because it will appear to be connected to the first router!
I once configured a router (that had vlan capability) without any interface except for a mangement wifi access with access only to luci: it acted as a pure switch even passing through non routables protocols.

On your AP, your ports would likely already be bridged... but let's see what's happening in the config file:

Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
grafik
Remember to redact passwords, MAC addresses and any public IP addresses you may have:

ubus call system board
cat /etc/config/network