Thanks for the feedback - on budgets and enterprises websites for their DR Locations it states the following. This seems the norm for all the major rental companies there
A major credit card in the name of the primary driver must be produced at the time of rental. This location accepts American Express, Carte Blanche, Diners Club, Discover, Mastercard and Visa. NOTE: Carte Blanche, Diners Club and Discover are only accepted as final payment. Credit Cards without raised numbers are not accepted in the Dominican Republic without purchasing LDW.