I don't think you have to worry about Bama calling for 2 reasons:
1) They have Nick Saban. I don't think they'll be firing him anytime soon, and I don't think he'll be receiving a better gig anytime soon. He's already done the NFL thing and didn't like it, so I think he'll be at Bama for as long as they'll have him, which will be a little while.
2) They already had him as a finalist before and chose Mike Shula over him. They were not happy with Shula, and the arrogant Bama fanbase would not allow for the AD to go back and basically admit they were wrong by hiring a guy they had a shot to hire a while back.
The Bama job will not be open for a while, and if it does come open, I really think they'd be too arrogant to go after him, and honestly I don't think he'll prove to have enough success nationally to interest them. As they showed with the Saban hire, they are not going to go out and just try to make a good hire from now on. They're only going to make a hire if they think it'll make a splash nationally. I don't know if I ever see Croom being that type of coach. Most of the coaches that become those type of commodities are either great national recruiters or have very innovative systems. Croom hasn't shown either of those yet. It doesn't mean he can't win or win big. It just means that I don't think he'll ever be the type of coaching hire that would be good enough to truly excite a fanbase like a Nick Saban or Urban Meyer hire did.
A good comparison would be Cutcliffe. He had success at Ole Miss, but his biggest attention for another job came from Kentucky. That's because he wasn't known as a national recruiter, and he wasn't known for being innovative or for being charismatic. Croom fits that same mold. He's going to have to win by recruiting in state, and he's going to do it in an old school style. That's just not going to draw the attention from outside programs, unless he starts leading you to multiple SEC titles, and I really don't see that.
In my opinion, I think the only job offers he could potentially receive that might be able to lure him away would be if an NFL team decided to take a chance on him, and that would take a pretty good amount of success.