Tango Air:
I have the pleassure to work as a ramp agent for a Handling company in Barcelona. And I deal with all the Italian airlines that fly to LEBL.
As a matter of fact, Alitalia has the policy of NOT taking any jumpseats. Of course, the cpt may accept eventually somebody but if he get caught, he'll have to pay to Alitalia the "extra crew's ticket". The price of normal ticket for that flight. That's why Alitalia almosts never accepts extra crews. And on the other hand, since Alitalia never takes jumpseats, the other Italian companyies don't want to accept extracrews from Alitalia and from other airlines.
That's what my experience tells me. In 80 % of the cases you'll stay on ground.
I've only seen two cases where the cpt accepted xtracrews: Alitalia and others sometimes allow pilots from Air Europa to jumpseat since this Spanish airline always (and when I say always is 100%) accepts jumpseats from any airline. Even Flight attendants.
And one time in a Volare Flight, the cptn was English and he wasn't very aware of the problems he could have.
Nevertheless, In Barcelona the ground staff it's not an obstacle.
Try to talk with the ramp agent directly at the gate (el coordinador).
Anyway TangoAir, what Airline are you working for?
Good luck!!
Boquinauer