Sounds like you're not logged in as the bot owner (IIRC only the owner can use the !settings command as default) and you can only specify one owner (I think!)
Specify the owner in the config file and then log into that character and it should all be ok. No doubt someone else will be along to tell you other ways to do it too
GBH
You can make alts on all your members, there is a setting to grab security details from the main char. So if you have configured your alts, and your main is owner, then you can manage the bot from all your alts, same as your main (they all have owner rights). This trick can be very usefull for all other superadmins and admins you install on the bot.