The answer to this depends upon the nature of the bath.
If it is a non-obligatory bath, such as a bath on Friday, or a bath to cool off on a hot day, then this bath does not suffice for wudhu. This is because performing wudhu for prayer is obligatory, while the Friday bath is recommended, and the recommended does not alleviate the need for the obligatory.
If it is an obligatory bath (e.g. after major impurity such as menstruation, intercourse etc), then a bath can suffice for wudhu, because minor impurity is included with major impurity, so if the major impurity is removed by means of ghusl then the minor impurity must also be removed.
The conditions for the obligatory bath sufficing for wudhu, are that nothing that would invalidate wudhu occurs during ghusl, and that you take water into the nose and mouth as well where it would normally go during wudhu so that all the wudhu areas are washed.
Some scholars say that doing wudhu during the obligatory ghusl is better and more complete, while doing it without wudhu only just suffices and isn't the best or most complete way.