I am writing you from the arrival lounge in ZRH. So it worked as the FB customer service promised.

I just showed the BCN ZRH boarding pass o the lounge dragon, she scanned it and the green light popped up.

I assume at this point that LX J is enough to access the arrival lounge, no matter wheter long or short haul (i didn't show her the BOG BCN boarding pass and in any case this wasn't a LX flight, but an AV one)

Other possibility would be that they opened to A*G. (i have A3 *G on the BCN ZRH pass)