Yes, you can chain auto actions. This is done using the autoactions_onAction trigger, which is fired when an auto action finishes executing. Its variables are as follows.
Code:
$_PLUGINS->trigger( 'autoactions_onAction', array( &$content, &$autoaction, &$user, &$variables, &$substitutions ) );
It is important that you condition against [var2_id] which is the auto action id of the auto action that just executed. If you don't you will end up in an infinite loop.
I think this really needs to be made easier though. Have added a feature ticket to implement chaining support, which would just let you select from a list of auto actions and it'll handle the chaining for you.
forge.joomlapolis.com/issues/7937