Googling led me to this page where the author had the same problem, and they found a solution in Safari Bookmarks Extractor. I can't test that it still works with version changes in both, but it probably does. Once you have your extracted bookmarks, you just use Manage Bookmarks -> File -> Import -> From File.
There's two versions of the app. The free one he's talking about limits him to 15 messages a day, and there's a $6/year version for unlimited text. Plus, they put ads in the app to make their money back. Otherwise, it looks to be fine.