There are some Bantam pitis here:http://www.javaauction.info/catalog_pilih.php?mode=pilih&id=CB&halm=2
Reference is made to
E. Netscher and J.A. Van der Chijs, De Munten Van Nederlandsch Indie
Millies, H.C., Recherches sur Les Monnaies Des Indigenes de L'Archipel Indien de la Peninsule Malaie
It seems that the sultanate used Javanese on their cash, and later Jawi (Malay Arabic).
The use of Arabic on your coin places it in the 17th Century.
I compared the ebay image, which is much clearer, with the images at the auction site above, here are the three coins, rotated to the same angle, side-by-side:
The identification is as follows:
BANTAM, PANGERAN RATU, ca.1651-1682 AD. Copper cash. Obv Legend in Malay-Arabic : "PANGERAN RATU ING BANTAM". Rev : Plain. Issued by the Fifth Bantam Sultanate, Sultan Ageng Tirtayasa, also known as "Pangeran Adipati Anom Pangeran Surya". His title reign is "SULTAN ABU AL FATAH ABDUL FATTAH MUHAMMAD SYIFA ZAINA M. ARIFIN, or "SULTAN ABUL FATH". Six-sided central hole. Mill-113; N/C-171. 3.65 gm; 25 mm. Very Fine.
It appears the previous sultan put his own name on the coin.
Realised price was approx $30 in Indonesia inclusive of premium. Where did you get yours?
The same coin exists in tin, which is rarer: