To bookmark RSS pages:

Go to the RSS view for the webpage you want to search. For example, go to www.nytimes.com and click the RSS icon at the right end of the address bar.
If there’s more than one RSS view for a webpage, clicking the RSS icon produces a list of available RSS pages. Choose the one you want.

Click the Add (+) button.

Type a name for the bookmark. For example, “Latest NYT Articles.”

Specify where you want to keep the bookmark. You can add it to the bookmarks bar, the Bookmarks menu, or to one of the collections of bookmarks, such as News or Travel.

Click Add.
When you click the bookmark, Safari displays the latest articles.