The theory of linear series on tropical curves, since its introduction by Baker and Norine about 10 years ago, has seen spectacular developments in recent years. In fact, the combinatorial systematic treatment of degenerations of classical linear series that the theory allows has led to the proof of many important results on algebraic curves. On the other hand, the introduction and study of a number of tropical moduli spaces of curves along with its realization as skeletons of their classical (compactified) counterparts allows for a deeper understanding of combinatorial aspects of moduli spaces and their compactifications. In this talk, I will explore this principle for certain moduli spaces of bundles on curves, as the moduli space of spin structures and their compactified/tropical versions.