Except as provided in Code Section 48-8-6, the tax authorized by this article shall be in addition to any other local sales and use tax. Except as provided in Code Section 48-8-6, the imposition of any other local sales and use tax within a county shall not affect the authority of a county to impose the tax authorized by this article and the imposition of the tax authorized by this article shall not affect the imposition of any otherwise authorized local sales and use tax within the county.