Don't assume that. The OP is in Europe, and thus not asking about the US Diners card. Which FF programs DIners supports varies tremendously from one country's Diners program to another country's Diners program. (Even Canada has way fewer choices than the US!)

While Diners may be a worldwide brand, that's only for acceptance (with the North American MC variation). The benefits, and spericially the rewards program, are customized by the Diners Club program specific to each country (or sometimes a group of countries).