Jetairfly is not a charter airline. It is a scheduled airline service operating for Jetair Belgium. You can buy tickets on Jetairfly's website. I think you enter the nationality in the online order form.
The difference between scheduled and charter airline is that charter airline sells the whole flight to the travel agency who then uses it with package deals. You usually can buy the seat only if teh agency cannot sell all packages and you have to buy the seat directly with the agency, not the airline.
With Jetairfly you buy seats directly with the airline (over the web, phone, etc.) and even though the airline is owned by the agency (TUI Jetair), you don't have to have package deal from the agency in order to fly the airline.
So yes Dominicans can fly the airline, provided they have all documents in order and have the return or onward ticket.
