I agree with Poli and Rusty. "Z" in Latin America is pronounced the same as "s" and most of us aren't even conscious of the nuances when the /s/ sound is accompanied by other consonants. For us it's always /s/
/s/
za
zo
zu
(as Poli explained, we don't really have ze, zi, but it's pronounced the same anyway)
ce
ci
sa
se
si
so
su
By the way, Poli, some of us prefer "cebra", even though we're called archaic.