Both are esters which are the condensation product, (meaning you lose a molecule of water when the ester is formed), of an alcohol and an organic acid. So ..... ethyl benzoate is synthesized from ethyl alcohol and benzoic acid, and benzyl benzoate is made from benzyl alcohol and benzoic acid. Well actually if you were to make it yourself you would use the acid chloride or anhdride and the alkoxide of your alcohol.
I think it's not such a good idea to try to interchange these 2, since they are pretty different chemically. The BB has 2 aromatic rings and the EB has a short alkyl group and 1 aromatic ring. This means that the BB is going to have better solvating power for nonpolar organic compounds, i.e. steriods.
