Define a shell function that uses the first argument to
man as a parameter
emacsclient -c -e "(man \"$1\")"
You could invoke the function without the alias (e.g.
macman ls), but it may be useful to set the alias for specific shells.
One note: You may want to assure your Man page is visible in the Emacs session as soon as it is invoked. Check the settings of the
Man-notify-method variable to achieve that. Either set it using
customize-variable, or set it explicitly as part of the function, i.e.
emacsclient -c -e "(let ((Man-notify-method 'bully)) (man \"$1\"))"
(Hat tip to @phils)