I am currently only making wine in one gallon quantities but I am looking at increasing that. As a beginner is there more room for making a bad wine if there is more of it?
No, the process is the same. If you sanitize everything correctly, you do not have more chances of spoilage, it will only take more time to rack and bottle.
Make sure you have the right size container (carboy or demi-john) to avoid having too much air in the head space. If your carboy is under-filled, instead of topping up with (another) wine, you can also use sanitized marbles to raise the level of the must and reduce the amount of air in the carboy.