I have 2 wow accounts - 1 that is attached to a bnet account that I use as my personal 'fun' botting account (pvp gear, rep, etc), and then a second wow account that has been dormant for many years and is not attached to a bnet account (from back when I used to 5box, I am the original owner). Would it be wise to make a second bnet account for my second account if I want to bot for gold etc? I have heard that they will only ban the wow account and not the bnet account if you get caught, but I don't want to potentially draw more attention to my fun account.
If you want to be as safe as possible, then be as safe as possible. Very few people that use this forum work for blizzard, and of those (you know who you are), none of them will ever tell you internal policy.