the artscroll footnote brought up the question: ketubot 89b discusses whether an arusa has a ketubah, why isn't this mishna (st 23b)a proof that the arusa has one - because it starts off by saying an arusa can't drink but still can't collect her ketubah. one answer they give is our mishna might just be saying that the wife loses a ketubah if the husband optionally took it upon himself(they quoted in the name of the meiri). however i don't get their other answer this is how it reads:"others explain that the basic ketubah obligation of two hundred zuz is in force from the time of arusin. It is only the other monetary obligations stipulated in the kesubah that do not become binding until erusin(rabbeinu chanane, cited by tosafos)" [i think that the way they wrote it, there must be a mistake]
ike sultan, west orange, NJ
Yes, I think you are right that there is an error there and it should read "It is only the other monetary obligations stipulated in the Kesuvah that do not become binding until Nisu'in" (Nisu'in is equivalent to Chupah - when the wife comes into her husband's domain). See Rambam Hilchos Ishus 12:2 who lists the obligations that the husband takes upon himself through Nisu'in.
KOL TUV
Dovid Bloom