I don't think you can make the blanket statement that this or that "is correct in English" for an obscure industry term like this. And NOBODY says "sini", if it's like the "cine" in "cinematographer", for the simple reason that nobody says "sinnymatographer". That's correctly pronounced in English, "sin-schwa-ma-togr-schwa-fer".

BTW, just try to tell the British oregano is "correctly pronounced in English" o-RE-ga-no, and not o-re-GAH-no...

[Up in (English) Canada, we'd also say "sin-schwa-muh", just like ADM sez it.]