The "git@" part is rendered unnecessary by putting "User git" in the SSH config for that host name.
There's also no rule saying that your SSH names have to be patterned like FQDNs. This is just personal taste, but to me, the ".com" is just extra junk to type. It could be reduced to "bob.github" or "bob-gh" or something similarly short.
While we're at it, the ".git" is optional too. We can reduce this down to something like:
git clone bob-gh:bob/bobsproject
But at the very least, leave the "git@" part off. ~/.ssh/config is already taking care of that part.