I've used react-intl; it uses the child context to pass the translations to react-intl specific react elements. I found this approach somewhat limiting, and a bit of a pain since you need to include the specific elements like <FormattedNumber /> wherever you want to put a translation. Looking at polyglot it seems simpler and more flexible. What I'd do is concatenate polyglot (make sure it's exposed as a global variable) and your translations as a separate script, and compile a separate one for each locale with the proper translations embedded in it. You can compile multiple versions of the same script using an environment variable to specify which translation to require for each build; like in this example for webpack. Then on the server, you'd check the locale in the request headers and add the appropriate script tag to the page, like:

<script type="text/javascript" src="translations-{{locale}}.js"></script>
<script type="text/javascript" src="bundle.js"></script>

When your bundle loads then you'll have polyglot as a global and you can use it wherever you need to in your components. This is similar to approaches I've taken in the past using globalize and browserify, and it worked out well.