CRS port isolation without Vlan with bonded ports

This is probably not exactly beginner but I am a beginner with mikrotik so I hope this is the right area for the post.

I have 3 24port CRS switches here that im trying to setup properly for a computer store.

2 of the switches have all their ports isolated using the port profiles and a uplink port that goes to the 3rd switch.

The 3rd one is where the fun starts:
ports 1-17 should all talk to each other (office network) (all port profile 3)
ports 19-20 is for a FTP server that does our backups, everyone needs to talk to it so its added to “trunk1” trunk port thing and this is added to the other groups (profile 2 and 3)
ports 21/22 is the connections from the isolated switches, (all port profile 2)
ports 23/24 is uplink (one is just left empty for future bonding maybe, so for now just work with port 24 as uplink.)

Currently all of this is working but what I really want to do is bond ports 19 and 20 since the ftp srever runs linux and has 2 network ports that can be set up to bond as well.

I have in the past set it all up so the ports are bonded and working but as soon as I try and isolate ports from each other I cannot add the bonded ports 19/20 into any group and no one can then talk to the ftp server anymore.
Is this just a limitation in the OS or am I just too dumb to set it up right. I’ve searched everywhere but I cannot find a proper guide that uses both isolation and bonding in the same setup.
All I can find is one or the other.

When attempt to bond ports 19 and 20 I get an error that they have a master port set to 24, so i set their master port to none and then bond them. This gives me bonding1 as a new interface/port.
Once thats done I see no way to now assign a master port to bonding1 nor can I add bonding1 as a trunk port.
How do I now add the bonded port into the other groups so they can talk to it?

Sorry if I explained things poorly, I’ve been learning this stuff myself through guides online.