If I remember correctly, at some point, two Forsaken meet,and one (the male of the two, I think) firmly holds onto saidin "Because compulsion can't work if someone is channeling." I'm not sure about this, because when Nynaeve beats Moghedien the first time, she slashes a weave of compulsion, and feels just the tip of it, as it fades away...Maybe it only doesn't work if the channeler is the same gender...Anyways, theoretically, Alanna would be able to compulse Rand if Rand wasn't channeling (with Spirit)and Rand could do the same thing.