I found a way to do this using Dropbox, but I'm not sure how safe or efficient it is. Try at your own risk
1) Quit safari on both machines.
2) Choose which machines bookmarks you want to use. Copy the folder from that machine: /Users/<your username>Library/Safari to your Dropbox folder
3) You might want to back up your Safari folders to another location in case this fails. Do that, then delete the folder /Users/<your username>Library/Safari on both machines.
Last and trickiest step:
Right now, both of your machines are missing the safari folder in the proper location. The safari configuration that you like the best is saved in your Dropbox folder.
The next step is to create a symlink from your the safari folder in dropbox to the proper location on each machine. For each machine, open up terminal and run the command:
Code:
ln -s /Users/<your username>/Dropbox/Safari /Users/<your username>/Library
Do this on both machines and then both of them will reference the dropbox location for the safari data.
I just did this myself, and it seems to be working. You sometimes have to load the bookmark manager to make changes appear from the other machine if safari is already active. Note that I have no idea how safe this is, and it could possible lead to bad things happening with your Safari (especially if you're using both machines at once!). The best bet for this to work is to make sure that only one machine is running Safari at a time, so there aren't two instances of Safari trying to read/write the files.
I had tried doing the symlinks with only the bookmarks.plist file, but whenever I made changes, the symlink seemed to disappear. Syncing the whole folder solved this problem, but is less efficient because all the other files are being synced now too.
Or, you could not take the risk and try switching to Google Chrome and use it's syncing instead
