How about providing a new option called "fireworks" while in town. As it is of a chinese custom, and origin, I think it seems fair to say that it fits in with the setting. Once unlocked, you may choose from several fireworks emotes. To get the ideas rolling further, an emote that allows someone to squat down and hold a sparkler is a viable option.
This option can become unlocked by redeeming an Aeria Funcard during a certain time frame. (3-4 days, or possibly a week). This will provide further promotion towards your partner franchises. I stress, though, the importance of only allowing Funcard purchases to allow the fireworks emotes to become unlocked. By allowing wireless purchases, it will most definatly take away from that franchise promotional aspect.
To accomodate those overseas, that do not have Aeria Funcards, I may suggest to you the option of Phone-in processing... I'm not a guru on billing accessibility, though, so I don't know the procedures or options available to those not in N.A.
I'll be sure to come up with more ideas!