HOME dir on another disk, how do I restore from TM backup?
Time Machine backs up symbolic links, it does not follow them. The operating system would not restore correctly otherwise.
Time Machine will back up multiple volumes, if you allow it to do so in Options. However, I believe you need to restore them separately. If you were to restore both volumes in the same configuration as the original, then it should work. Linking anything through /Volumes is a bit fragile, so you might need to adjust the symlink after restoring both volumes.