Ok, so Sam's con pool is 13, plus Snow's 2 gets him to 15. Splitting it into two rolls; the bartender's more likely to pick up on things, so he gets 8, while the bouncer gets 7.
8d6.hits(5)=3, 7d6.hits(5)=2Not Sam's best performance, I'm afraid (I think that'd be the sheriff way back in the beginning!), but decent.
As for the question of why Sam splits--I'm not really sure. The RAW talk about splitting dice pools for multi-weapon attacks, multi-target attacks, etc., but the only description for what happens when trying to use charisma skills on multiple people is on page 130:
If the character is attempting to influence a group of NPCs who have no designated leader, the Opposed Test applies to the whole group—use the highest dice pool available among the members of the group, then add +1 for each extra person (max +5). Groups tend to react as a whole, with reluctant members drawn along by enthusiastic ones. Alternatively, the gamemaster may appoint a leader or a “ringer in the crowd” and base the success or failure of the endeavor on that character’s reaction to the player character.
Which makes me think that Sam's roll (all 15 dice) should be opposed by the bartender's pool plus one
1 for the bouncer. But ultimately, I'm willing to let the GM decide.
1 Side note: The RAW don't indicate if this bonus is an extra die in the pool, or just a guaranteed hit. I could read it either way and feel like it made sense.