Not extremely similar, they're probably on opposite ends of the Romance languages spectrum. Spanish being more Arabic-influenced and Romanian being more Slavic-incluenced. But as far as I know, Romanians have it easier understanding Spanish than the other way around.
I think this is more about the cultural links, though. Romanians seem to love Latin American music and TV shows, and Reggaeton is actually quite popular there. So it's no surprise this would be a hit.
Well done, Romanian fans! I hope tomorrow we'll wake up to a bunch more #1 spots.