Unless you're in a no limits relationship, which in most cases probably isn't safe or sane even if it is consentual, then the bottom is always in control and always TFTB in reality!

D/s relationships are just illusions of control for the purposes of acting out bdsm fantasies. If the quality of the illusion is good, then it will seem like the dom is in control and all should be well. If the quality is poor, it will appear the sub is TFTB and the result probably won't be satisfying play time. The total illusion is the sum of the ability of the participants to play their roles according to the pre-determined rules and limitations of the game.

But having said that, once the rules are established, if the bottom tries to control when, what or how things happen within the confines of the limitations and rules already established they are TFTB. Whether or not you or your partner(s) can enjoy this or find this acceptable is a personal and subjective matter.