Hello,

I currently have a vps at a hosting company with several V4 IP addresses and I have installed Routeros on it.
I also have a Mikrotik router at home, connected in bridge mode to my Freebox (my ISP's router). I've looked at several tutorials on the Internet to create a GRE tunnel and I must admit that I'm a bit confused about certain points concerning the routes (I imagine that these are the routing tables).

Here is my current configuration:

IP of my VPS where my mikrotik router is installed: 45.xx.xx.140
An additional IP from my vps: 45.xx.xx.90
(Their gateways are different)

On my router at home:
Local IP of my router: 192.168.1.16
My public ip: 82.xx.xx.212

Could someone help me understand this concept of routes on mikrotik so that my tunnel can work? Thank you!

Could someone help me understand this concept of routes on mikrotik so that my tunnel can work?

You didn't ask the question clearly.
You have not formulated the problem you are trying to solve with the GRE tunnel.
You have a large knowledge gap in the basics of networks, in particular the routing section.
A network has at least three basic parameters: network address, netmask and gateway. For your home network, the router (gateway) is Freebox (my ISP's router). All devices on your network access it when they try to send a packet to an IP address that is not on your network. The Microtik takes no part in routing because it is in bridge mode. Therefore, any routing rules you write on it will only apply to packets sent by the Microtik itself.

Local IP of my router: 192.168.1.16

Is this the address of the router or the switch? When a router is set in bridge mode, it acts as a simple switch. It is not a router and does not route networks.
PS Judging by the status of the tunnel in your screenshot, it is able to "running".