I have used Skyteam PC Travel desk and we are both right

I think you are talking about flights AF394 and AF393.
Unfortunatelly I was looking at 11.11. when I should fly and there was no connection like that only that one with EZE AEP change.

I've checked that again on AirFrance site.

Anyway in mean time I called AirEurope in Spain and got form them same answer as from AlItalia in Serbia: No matter they are both Skyteam, they cannot provide me with "partner" connection from BEG to MPX or FCO from where AirEuropa flyes.

I decided to take two separate cards and go over Milan. Constantly with Sky team, no codeshare (at least not with AirSerbia) so I'll have two luggage policy 100%.

Sorry I made so much confusion, I had to find that ticket fast and travel agencies from Serbia are giving me only headaches about choice.