How do I patch a tube's ribbed area?
More careful buffing - the ribs stop the sandpaper/scratcher from getting into the butyl rubber and exposing raw rubber, so the vulcanising agent can't work so good.  

You don't need to buff the ribs off completely, but scratching up beside the ribs helps a lot. 

Also, over-size the area that you cover when you spread agent.  Those orange edges should be stuck down firmly.

Another help is to use a larger patch in these areas, but it means more buffing because more surface area.  You can also rotate your patch 90 degrees to cover the length of the ribs more.

Also make sure to wait 5-10 minutes after applying vulcanising agent, before pressing the patch on.  Then press patch firmly.  I use a roller the width of two coins, but a large round coin works fine too.