Those are good questions. I think Bella only called Sam an Alpha because he actually ENFORCES rules and commands, and Jake just says, "If you want to, do this." So Jake's Alpha but NOT an Alpha, if that makes any sense. =) Just that he never enforces anything.
And Jake and Sam are cool now but I don't remember Jake ever going back to La Push . . . and what Sam was trying to do (kill Bella and the Cullens) really hurt Jacob, and now he is part of the Cullen family, so I'd say he didn't join Sam's pack. They've just been through too much since the rules Sam enforced and Jake's being Alpha, so Jake has his pack and Sam has his.

Thanks for the response.
He went back at the end of the book...I was confused.

I LOVED Breaking Dawn soo much that im reading it again for a 2nd time. :-)
email me.

well sam was supposed to be the beta but he was the first so he`s the alpha but later jacob(beta)gets questioned by bella and he admittes he`s supposed to be the alpha but he doe`nt want to be but soon he make his own pack.well jacob went back cuz he did`nt like his pack following him every where and that telepaphy you get it.

I'm confused. I thought Jacob didn't go back to Sam's pack. He remained the alpha of his with Seth and Leah, and Embry and Quil ended up joining him. This was mentioned in the last few pages of Breaking Dawn. Whether or not he stayed in La Push - that I don't know.

in thought so to

I'm reading it for the third time and it still confuses me.

There were permanently 2 packs and 2 Alphas, one for each pack. As niya429 says, Jake stays in his own pack with Seth and Leah, and they're joined by Embry and Quil.

I think Jake would stay in La Push for a while, because his family's there. But eventually the Cullens would have to move again and Jake would move with them because of his imprint.