Two selected examples have been chosen to illustrate the ability of non-resonant Raman scattering to probe phonons in hexagonal GaN-AlN artificial structures. The angular dispersion of polar phonons is investigated in a long period GaN-AlN superlattice and compared with the results of calculations based on a dielectric continuum model. On the other hand, the Raman signature of the self-assembled GaN quantum dots and of the ALN spacers of a multi-layered struct;re is used to determine the strain field in the stucture. The dots are shown to be fully strained on the ALN lattice parameter while the spacers exhibit on the average a slight tensile strain.