When my opponent revealed Black Market as a bane to Young Witch, it didn't show in the log (and either I wasn't paying attention, or there wasn't anything on the main screen indicating that he revealed it). The only way I could tell he had revealed a bane is that he didn't gain a curse. Game had YW, Black Market, KC, and Upgrade in kingdom but I forgot to get the number.
Edit - I just had another game today in which the log also did not show whether a bane was revealed to Young Witch.
Here's an easy one to fix now.
Luckily, the log tells you that they gained a curse if they did so. If it doesn't, Royal Carriage is not recommended. 8)
But I agree: the log should explicitly mention the bane reveal (or Lighthouse or Champion).