By default there is no visible way to embed the all company-feed on a page, for example in a SharePoint Online portal.
To accomplish this, you can go to a random Yammer group and get the code to embed the feed: “Embed this feed in your site”.
The only thing that needs to be changed here is the feedId-parameter. You need to change it to “all“.
That’s it, you can now embed the all company feed on any page you like. 🙂