This paper investigates an ambient energy harvesting system operating under specific airflow velocities, utilizing two flexible cantilever beams terminated with cylinders and equipped with piezoelectric transducers. The system vibrations are induced by the vortex shedding phenomenon, modelled as a Van der Pol oscillator. The analysis covers both repulsive and attractive magnetic configurations. Specifically, the impact of the cylinder diameter and the body mass ratio μ on the generated voltage and broadband performance was examined. The results indicate that increasing the cylinder diameter expands the flow velocity range in which the moderate output voltage is achieved, reaching values up to 25 V. The application of an asymmetric mass ratio (μ = 0.5) further enhances the system’s bandwidth, enabling effective operation across a range from 1 to 14 m/s. Optimal performance was observed for a 0.12 m diameter cylinder in an attractive configuration with μ = 0.5, where the peak power output reached approximately 800 μW. This study confirms that by optimizing the magnetic configuration and geometric parameters, it is possible to significantly increase the efficiency of Vortex-Induced Vibration (VIV) energy harvesters utilizing piezoelectric transducers and magnetic interactions.