I’m not sure I fully understand the question, but in general, the id attribute of your previous inline templates should map exactly to the template path in ember-cli.
So components/blog-post should be found at templates/components/blog-post.hbs.
To render your foo/bar.hbs template in another template, you could use a partial like so:
Pay attention to naming convention. I was struggling with {{partial}} and think I didn’t follow the naming convention. In my case it’s dash vs camelCase
Dashes for
file names
folder names
html tags/ember components
CSS classes
URLs