I found it very annoying that bash won't fully tab-complete a linked directory; it omits the very important character / at the end.
For example, if I type in
$ cd ~/Doc
and press [tab], it will auto-complete as below
$ cd ~/Documents/
with / character at the end, since this is a directory.
Unfortunately, however, if I create a linked directory
$ ln -s ~/Documents ~/linked_Documents
$ cd ~/linked_Doc
and again press [tab], it will auto-complete to
$ cd ~/linked_Documents
without / character.
The solution for this is found here, which is reproduced below.
Simply add the following lines into ~/.inputrc and restart your terminal
set mark-symlinked-directories on
That should do it!