Transfering gold between two accounts can be "detected" as gold selling. One of the safest ways to do this, however, when just doing it between your two accounts, is via guildbank. Large numbers and random trades is often traced by blizzard (face to face), so I would avoid that.
Ban is always an option. If your botting account gets caught, there's a big chance your non-bot will be caught as well, as he's been trading gold with it. However that's not for sure. In general I would just bot smart and use the guildbank for gold transfers, and not do it in big amounts at a time, and then i wouldn't worry that much.
Good luck. ^^