Should we include information in tags in the body of our text?
Tags like the question still get people to comment whether they are using 32bit or 64bit. So should we still add more to the question by adding this to the end of our questions for readers who don't look at tags?
Almost certainly yes. While tags are useful for searchability, at the end of the day they're no replacement for attempting to describe your environment. In addition, not everyone reads the tags at first (I often don't) and having it in the question body improves readability.
64-bitshould be for questions that are specifically about the bitness of something. They shouldn't be placed on every question that uses the 32 or 64 bit version of a software.