A mixture of a cationic surface active ionic liquid, [C(8)mim]Br and anionic surfactant, [Na]DBS has been shown to form unilamellar vesicles in water over an exceptionally wide mole fraction range of [C(8)mim]Br (x(1) = 0.2 to 0.8). Formation of vesicles has been evidenced from transmission electron microscopy (TEM), cryo-TEM and atomic force microscopy (AFM) imaging. Cryo-TEM imaging of an equimolar mixture showed multiarchitectural unilamellar vesicles (spherical, tubular, and ribbon). Such complex architectures were earlier reported for Janus dendrimers of different structures (Science, 2010, 328, 1014). The synergism between oppositely charged single chain surfactants to form bilayer structures has been explained based on the evidence of pi-pi stacking interaction from 2D NOESY measurements, Coulombic interactions from zeta potential measurements and magnitude of interaction parameter from the critical aggregation concentration. The aggregation concentrations were measured from tensiometry and fluorescence using pyrene as a polarity probe. The phase behavior at different mixture compositions has been revealed from turbidity measurements and visual inspection. Hydrodynamic radii of self-assembled structures in the bulk solution phase were measured from dynamic light scattering. Vesicles formed have been explored as delivery vehicles for proteins using bovine serum albumin (BSA) as model.