[git clone --bare] created a bare repository from my working directory but there are no remotes or branches set to [make the original Git use] the new bare repo ...
That's quite normal.
When you make a clone, your Git remembers where it cloned from. It does not modify the source at all; it makes a new repository, more or less as if you ran the following sequence of commands:
mkdir new-repo.git cd new-repo.git git init <flags> git remote add origin <url> ...
(where <flags> represents the --bare flag, and <url> represents the URL from which you are cloning).
If you want to affect some existing repository:
cd existing-repository git remote add <name> <url>
where <name> is the name you want to use—maybe origin, for instance—and <url> is the URL you want to associate with that name.
Note that this merely adds a name, without first contacting the given URL to see if there is a Git at the given URL. So if you have a typo here your next git fetch will fail, when it tries to use the URL.
Note also then when you make your initial bare clone, you may want to use the --mirror option, if the source from which you are cloning has more than one branch. You may or may not want to run git remote remove origin in the bare clone afterward, to remove from the clone its memory of where it came from. (In normal operation, remembering is harmless, but (a) if you used --mirror and (b) someone tries to run git fetch in the bare clone, this could be bad.)
