There is in fact a significant difference between allegory, in Philo's sense of the term, and typology. Allegory postulates a parallel, correspondence, or resonance between two sets of ideas; typology (broadly speaking) postulates a parallel or correspondence between two sets of events or persons.
James Smart expresses this contrast in theological terms. "Typology is distinguished from allegory by the fact that it fastens onto the historical reality of the event, where allegory disregards the historical reality and draws out a contemporary meaning that has nothing to do with the original event."A. Thiselton, Hermeneutics: An Introduction (Eerdmans 2009), 84.