Winkiepinkie,
"Can anyone confirm that this is allowable in a JAA state or is the big bad Italian captain seriously bending the rules."
I would read JAR OPS 1 to check whether this is illegal according to JAA regs.
As far as what your friend told you, believe him. In Italy it is relatively easy to get jump seat rides (provided you know someone).... though personally I would not consider that "seriously" bending the rules. IMHO there is no rule bending, since it is ultimately up to the captain of that flight.
Anyways, there could be far more serious rule infringements than a captain allowing selected individuals fly in the cockpit...
palgia