89 - Ochenta y nueve
It is clear for me now that eight is delapan. The 88 we would say it in Spanish then ocho ocho (delapan delapan) but we only use such a form when we are trying to give a phone number in a kind of easy way. You know, children and uneducated people has some difficulties with numbers and just for being sure they catch it we use the digit by digit form. Most used form in radio or TV ads.