Catalysis of the reaction: 2-oxoglutarate + O2 + 7--wyosine37 in tRNAPhe = succinate + carbon dioxide + 7-(2-hydroxy-3-amino-3-carboxypropyl)-wyosine37 in tRNAPhe.
tRNAPhe (7-(3-amino-3-carboxypropyl)wyosine37-C2)-hydroxylase activity