Not fully convinced. I could not find a location that gives the proper pronunciation. Would still like to know if the prefix wa glues together with the first vowel to a long vowel or if they remain separated?
Phonetical description hints that hiatus (a number wovels in a row) in Kiswahili is eliminated with kinda "glottal stop" - which slightly separates these two (in this case) sounds.. so i'd consider it as two separate sounds which can lazily! be pronounced together.