Simplest way to visualise this link is as a very long ethernet cable. So the CPE220 point to point link extends the connection from your router or switch where your smartphones are connecting, to the remote location hosting your IOT devices, it does not then provide the local WIFI as well .

You will require another device at the remote site to act as the wifi access point (AP) for your IOT devices. Something like a TL-WA801ND or TL-WA901ND would be a suitable AP for your remote IOT devices unless you need an outdoor model like an EAP225 Outdoor. You need this additional AP device because the CPE220 has a very directional antenna and wont provide good coverage for your devices also it will be in client mode and not acting as an access point, use it just for the long link as designed and shown in your diagrams. Adding a connection to the switches shown in your second diagram to an AP at each end would provide the local WiFI.

Such a solution is shown in the scenario at this link, it shows a local AP in the second building as I describe above.

You asked if it could be the same wifi at each end, yes as you can configure the same SSID on the access points at each end of the link and they will effectively be connected together via the CPE220 behaving as a long ethernet cable (in reality it will be better than a long ethernet as the bridging function built into the CPE220 will prevent non-broadcast traffic from being needlessly sent over the link).

The Advanced Techy bit:

For traffic isolation you might wish to configure a different SSID and VLAN or different physical subnet for the IOT devices and configure yout firewall or router to allow the smartphones to access the IoT devices but prevent the IoT devices from connecting to the internet or other devices on your network.

Thank you for your reply.
If I understand correctly, you need a WiFi router on the IOT side to ensure good local coverage of Wifi, because of the directivity of the CPE220.
But the problem is it not the same for the SmartPhone side?
In this case it would take a CPE220 on each side.

Thats correct, think of the CPE220 just for the point-to-point and use an Access point (AP) for the local WiFi exactly as your last picture shows.

If you want internet access as well connect the devices at the smartphone end to your internet facing router/switch, the router will also provide DHCP to allocate IP addresses to your devices so they can talk to each other unless you plan on them all being statically addressed?

If you do intend to use the EAP225 outdoor as your picture shows you can also use the POE passthrough on the CPE220 to power both the CPE220 and EAP225 from a single source (but check the power consumption and specification of your power supply first!)

Thank you for your reply.

I assume that all APs (CPE220 and EAP225) must be on the same SSID.

And WIFI modes:

CPE220 Smatphone side:     Access Point

EAP225 Smartphone side:   Client???

CPE220 Iot side:    Client

EAP225 Iot side:   Client???

Is it correct ?

Ok I updated my schema.
Thank you again for your help.