I used ProfileCreator to make my initial com.google.Chrome.plist. I then opened the plist in BBedit (personal preference, but save the hassle of having to convert the plist to upload).
I adjusted the Bookmark plist setting with the toplevel_name key value (you'd probably also use the children key value).
Since I needed my bookmarks to be on every user's machine, I uploaded the plist into Application & Custom Settings in Configuration Profiles.
You'd use a slightly different method if you'd like user's to be able to edit the Bookmarks.