Here, the basic requirements are the same: You'll simply need to play Mafia Wars 2 long enough to get to Level 5 to be eligible for a prize back in Pioneer Trail. You'll likely need to head into Mafia Wars 2 from the in-game link within Pioneer Trail to force your progress to "sync" back over, and you'll receive a free White Lion the next time you log back into Pioneer Trail after reaching Level 5. However, here's where things become different. Not only will you receive the White Lion in Pioneer Trail, but you'll also receive one within Mafia Wars 2.
The White Mountain Lion item will appear in your Pioneer Trail inventory automatically when you next login to the game, although the promotional pop-up will still likely appear. Don't fret - you have received your prize. It just appears that whatever trigger exists to "delete" this pop-up from your Homestead hasn't been turned on. As for the White Lion in Mafia Wars 2, this itself seems to be bugged (funny, that), as I've yet to receive mine anywhere in my game. It could be that it either hasn't been coded into the game yet, or that it simply takes time to "unlock," but we'll keep an eye on things and let you know exactly where it ends up.
Either way, if you have no interest in playing Mafia Wars 2, rest assured that you'll receive your prize in Pioneer Trail, which is then all that will really matter. Just remember to try out this cross-promotion fast, as apparently these White Lions won't be around forever.
Have you played Mafia Wars 2 long enough to unlock the White Mountain Lion in Pioneer Trail? Did you receive the Lion in Mafia Wars 2 as well, or are you still waiting? Sound off in the comments.