This smells of
premature optimization to me.
Why are you even worrying about little things like this? Unless a profiler told you that this is your performance bottleneck or all you are ever doing is exchanging
bools, then this is likely to be of no concern
what so ever in the real world.
If you are employing
any kind of compression to your serialized output stream, then that's going to take care of the redundant bool bits for you easier than anything else. Even if you are not, than the rate of bools to other significant amount of data is likely to be so low that a few wasted bits are going to be lost in the noise.
Seriously, don't worry about it and don't waste your time optimizing it - in the grand scale of things it is going to be utterly irrelevant and a waste of time.