Absolute photoionization cross sections for the Rb 2+ ion were recently measured at high resolution over the energy range 37.31 eV -44.08 eV, with autoionizing Rydberg resonance series identified, using the photon-ion merged-beam setup at the Advanced Light Source (als) in Berkeley (Macaluso D A et. al. J. Phys. B: At. Mol. Opt. Phys. 49 (2016) 235002; 50 (2017) 119501). Detailed photon-energy scans taken at 13.5 ± 2.5 meV bandwidth illustrated multiple Rydberg resonance series associated with the ground and metastable states. Here we present theoretical cross section results obtained using the Dirac-Coulomb R-matrix approximation with a detailed analysis of the resonances. The calculations were performed for the 3d 10 4s 2 4p 5 2 P o J , J = 3 2 ground state and the corresponding 3d 10 4s 2 4p 5 2 P o J , J = 1 2 metastable level. Results from the large-scale calculations are benchmarked against the als high-resolution measurements and reproduce the dominant resonance features in the spectra, providing confidence in the theoretical work for astrophysical applications.