But personally, I don't follow a specific set of transliteration system.
I prefer the system where each kana is assigned to one unique romaji. I.e. I will retain "wo". But there are exceptions.
I use "wa" instead of "ha". And also for certain words like Tokyo, I use the more commonly...
I don't really know how to describe on how to read it, but when I read it, it will be something between "o" and "wo". The "o" sound will not so sharp, but the "w" sound is sort of, not silent, but padded.
Actually they used both... One clear vinegar which I presume is rice vinegar used while cooking, and the yellowish corn syrup vinegar which is a bit viscous used when preparing the rice for sushi.