Unless the OP is you, this appears to be a known issue
Sync is both ways so there's something not working as intended. It could be that the computer hasn't synced yet, to confirm this, you can press the Sync Now button in the Firefox button (if you are in Mac it's under "Tools").
If after that it doesn't work, I will recommend you to check in the logs if there's something that is not being downloaded to your computer.
Another less optimistic post
The phone bookmarks are not compatible with desktop Firefox. If you recover browser.db from the Firefox for Android that file contains your bookmarks. However it requires SQLite to read the file.