As far as I'm concerned, there is NO permanent fix to the issues with webbookmarksd.
In the last 6 1/2 months I have fixed this issue 3 times, after deleting my bookmarks database on my MacBook to ensure a clean non corrupt version, doing the same within my iOS Backup using the outlined methods iBackupBot, then setting the phone up as new. The fix lasted approximately 1 month before I had to fix again and did this a couple of times before going the next route.
Specifically, since April, I've set up my phone twice completely as new, manually putting everything back on my phone, not restoring anything whatsoever from a "cleaned" backup, and turn off and do NOT use iCloud syncing of Safari data on my iPhone as well as NO iCloud syncing of Safari data my MacBook. Webbookmarksd has begun to run amuck within a week each time.
Additionally, even though syncing of Safari data is off everywhere anytime Safari is launched on my iPhone the "webbookmarksd" process starts up and continues to run until I either kill the process or force close all running apps and reboot phone.
One would think that if iCloud syncing of Safari data has been turned off, then webbookmarksd shouldn't continue running amuck, unless of course the more obvious being that there several other integrated processes making calls to webbookmarksd that have nothing to do with the syncing of bookmarks, reading list and VISITED App Store pages.