No it is mainly italian: generally from Sicily. But two other groups of Tona are in Northern Italy: near Milano (Milan) and another group near Venice, in Treviso area. This name could come from the given name "Antonio": "Toni" and then a matronimyc "Tona". But this is not so sure! However there no links between all the Tona families. The Tona I know better are those from Sondrio area (Lombardy). But at the moment I am not sure about their origin.