If you have the charge pump in the circuit, it can only accept 9V. The charge pump does not regulate the input voltage. If you supply more than 9V, you risk breakdown of components. An 18V input would raise the charge pump output to about 54V.
Edit: the LT1054 can accept up to 15V. However, unless you’re comfortable with ensuring all of your parts are rated accordingly and you understand the function of the charge pump block, I strongly advise against providing anything other than standard 9V input. You could get the 18V option by tapping the second to last pump stage.