Grab bonus combat maneuver bonus stacks with grapple maintain bonus?

[Joraiem]

In my current game I'm playing a druid who just had his animal companion die. Near the end of it's life, I learned that animal companions are pretty good and grappling tough enemies and making them easier to hit.

I was looking into constrictor snakes and saw that with the grab ability, they get a +4 to start and maintain a grapple. Someone also told me that when you start a grapple, you get a +4 to maintain it. Does this stack with the bonus from the special attack?

[Beldaru]

Yes, it should. The grab ability is a separate bonus from the bonues you get for maintaining a grapple (which I believe is a +5).

Grapple:
If you do not release the grapple, you must continue to make a check each round, as a standard action, to maintain the hold. If your target does not break the grapple, you get a +5 circumstance bonus on grapple checks made against the same target in subsequent rounds.

BTW, my sincerest condolences on losing your animal companion