What you are looking for is the hgfs backend. whenever a state.highstate is called, the master will pull from bitbucket and send it to the minion. A basic configuration would be the following:
fileserver_backend:
- hg
hgfs_remotes:
- https://self@bitbucket.org/self/salt
hgfs_branch_method: branches
There is unfortuntaley a lack of documentation about how to configure hgfs so doing anything more advance may require you to dig around. Good luck.
Note for future readers: I am not sure whether the minion or the master pulls from bitbucket.