The Arpasing method is English only at the moment, though a tool was recently developed for labelling phonemes that may, with further development, be adapted for use in a multilingual OTO generator.
I'm not intimately familiar with Portuguese, Spanish, or Latin, though I can look up the phonemes and put a list together that way. You may want to look at existing lists for those languages to find common phonemes and phoneme combinations, as well as any features that are particular to a specific language.