I've not tried to load the 32 bit and 64 bit versions of the OS myself, but I would imagine that you will need to load the programmes you want onto each version that you want to run it on. I don't think sharing programmes between the different OS versions is possible.
I assume that when you boot your system you choose whether you want to run 32 bit or 64 bit. As such each system will not see the other one.
That is how I see it, but if I am wrong I'm pretty sure that someone else, more knowledgeable, will let us both know.