The Romanites were overwhelmed by the influx of Spanish Jews in 1492 and most of them were absorbed into the Sephardic culture. Several pockets of Romaniote culture remained, most notably in Yanina and Crete.
The name "Romaniotes" appears to come from "Roman," denoting Jews who were part of the Roman Empire.
Recently genetic testing has been done on Romaniote Jews in Old Age Homes in Rome and there seems to be a common ancestry between Ashkenazi Jews and the Romaniotes. Romania was a province of Rome and Romanian is a Latin based language. We Ashkenazi Jews are all related to the Romaniotes but it seems that they have the most direct blood lines to the original Judeans.
There's a small Romantiote synagogue which was established by Jews from Yanina on the lower East side of New York. Most of them were deported from Greece by Kurt Waldheim and died in Polish death camps almost immediately after deportation because they could not survive the harsh Polish Winters.
You might also want to check the book "Classic Cuisine of the Italian Jews" which gives a little history on the Italian Romaniotes. There's also a film which is called something like "Victory/Triumph of the Spirit" which is based on the life of a Greek Romaniote Jew who survived the Polish Concentration camps as a boxer. There's more out there but this is what I can recall at the moment.
The Romaniotes should be looked upon as an indiginous Greek Jewish community. Fourteen centuries later, as a result of the expulsion from Spain, large numbers of Spanish Jews settled in Turkish domains which included Greece. Because of the greater sophistication and education of the Spanish Jews, many Greek Jews adopted their traditions and became Sephardim. A few in some of the more remote locations in Greece retained their indiginous traditions; these are the Romaniotes. There is a Romaniote synogogue on the lower east side in Manhattan and another in Israel. I don't believe that there remains a Romaniote synogogue in Greece.
Irwin M. Berg