We demonstrate a versatile bismuth-doped fiber pulse source that is seeded by a mode-locked fiber laser operating in different regimes with different net dispersions in the same cavity, including square wave noise-like pulse regime with anomalous net dispersion at 1331 nm and multi-pulse soliton regime with normal net dispersion at 1320 nm. The versatile pulse evolutions and the multi-pulse dynamics in these two regimes are investigated under different pump powers or polarization states. The seed pulses are then amplified by a bismuth-doped fiber amplifier, which boosts the pulse energy to 21 nJ with a slope efficiency of 21.3%, without power saturation, anticipated to be useful for practical applications.