I have found the way: aliases must be in .bashrc
I connect using (Macintosh) Terminal, and when logged to the online server I just "activate" a new shell typing "/bin/bash".
In this new shell I have the right Perlbrew Perl, an all the alias, because this new shell takes everything from the .bashrc file.
What confused me was that "a new shell" is not really "a new terminal window" as I was expecting, but a new "process", and this new process, obviously uses .bashrc as a start point.