Safari syncing with iPad, iPhone, iMac..tabs, reader..

my ipad, iphone, and mac all sync using iCloud. however, one thing that does not fully sync is my SAFARI BOOKMARKS.

my READER bookmarks synced in the past but are not syncing now. also, my ICLOUD TABS are not showing what is open on other devices. AND...some things are syncing while others are not. for example, some articles are not sycing with iPad/iPhone but are on my iMac. so..when i save to reader from ipad/iphone, it does not save to imac, and vise-versa,....

please help!