Sync Safari bookmarks between computers
Ahhh... I don't know what happened but somehow the bookmarks that I edited on the iMac just didn't reflect on the MBA at all. I am only using really the Bookmarks Bar and don't keep bookmarks anywhere else.

What I did:
Went into iCloud settings on the MBA. Switched Bookmarks syncing off. Then back on. It asked me if I wanted to sync and merge the local bookmarks with the ones in the cloud. I said yes. It synced, and I got double bookmarks everywhere (iMac and MBA). Then I just deleted the duplicates, and all seem synced and well on both devices. I sync with some iPhones, iPads too and it seems ok. The bookmarks there appear in the "Bookmarks Bar" subfolder.