iCloud sync between iPhone and iMac
bookmarks on iphone are not avaiable on Imac
iMac, OS X 10.11
As per this article https://support.apple.com/en-in/HT207689
When you turn off an iCloud feature on a device, information stored only in iCloud for that feature is no longer available on the device.
Sometimes when you turn off an iCloud feature on a device, you can choose to keep a copy of the feature’s information on that device.
Before you turn off a particular feature on all of your devices, or before turning off iCloud completely, you can make a copy of the information you keep in iCloud on your computer.
See these articles https://support.apple.com/en-in/HT204230
https://support.apple.com/en-in/HT203519