You can specify the template as a dependency using the text! module like you have shown. I do this with Mustache Templates.
However Require.js does not explicitly support css files.
Here is the official explanation, it’s explained pretty well:
http://requirejs.org/docs/faq-advanced.html#css
Edit: Feb 2012.
Templates such as handlebars can also be precompiled and included just like any other JS module
http://handlebarsjs.com/precompilation.html
Edit: August 2015
If you’re after this sort of modularization you should look into webpack and specifically css-loader. I’m using it to pair .css files with .jsx files as a unified “module” and extract the relevant CSS into a single stylesheet at build time.