Each warrant issued under Section 8-1-11 may be made payable at the time fixed in the warrant and shall bear interest, payable only out of the taxes against which it is drawn, at a rate not to exceed the maximum rate authorized by the Bond Authorization Act, as amended at the time of the making of the contract, from the date of its issuance until paid, or until notice that the money for its payment is available, and that it will be paid on presentation, is given by publication in one or more newspapers published in the municipality, or, if no newspaper is published therein, then in one or more newspapers with a general circulation within the municipality. In municipalities with less than 500 population in which no newspaper is published, publication may instead be made by posting a notice in 3 prominent places within the municipality. However, a lower rate of interest may be specified in the warrant, in which case the interest shall be computed and paid at that lower rate. The amendatory Acts of 1971, 1972 and 1973 are not a limit upon any municipality which is a home rule unit.
     With respect to instruments for the payment of money issued under this Section either before, on, or after the effective date of this amendatory Act of 1989, it is and always has been the intention of the General Assembly (i) that the Omnibus Bond Acts are and always have been supplementary grants of power to issue instruments in accordance with the Omnibus Bond Acts, regardless of any provision of this Act that may appear to be or to have been more restrictive than those Acts, (ii) that the provisions of this Section are not a limitation on the supplementary authority granted by the Omnibus Bond Acts, and (iii) that instruments issued under this Section within the supplementary authority granted by the Omnibus Bond Acts are not invalid because of any provision of this Act that may appear to be or to have been more restrictive than those Acts.