Flag based access to ChanServ does not currently exist for Anope. It also doesn't really make alot of sense either. If you grant someone the ability to ban a user, there is no reason that they can't kick them as well. Same is true for Channel Ops, if the person is trust worthy enough to have Op Status, there is no reason that they can't have kick/ban or any of the lesser cmds as well.
What good does it do to allow a person to be able to ban, but not kick? or even worse would be the ability to kick but not ban or the ability to op themselves but not voice another user? If you think about it .. it's rather silly.
Lets look at some sane flag combinations:
kick and ban but no modes (other than ban), This already exists with HalfOps.
can talk in channel even while it's +m, This already exists with +v
can change channel modes and remove users. This already exists as a ChanOp.
As you can see, logical access already exists. To restrict them would easily create confusion. Not to mention that most users are on IRC really don't like to spend their time learning and configuring Services, they just want to chat.