Many people may not be aware that WordPress will output an RSS feed of all posts with a particular tag. This is great if you want to feed a particular page with posts just tagged as ‘WordPress’ for example.
Get an WordPress RSS feed from a tag
If you have changed your permalink structure using for example using /%category%/%postname%/ then the feed URL would be:
If your using non fancy permalinks (the WordPress default) then the URL would be: