Soothsayer is occasionally given as a translation here and it often suits the situation better. Maybe in the context of 'bard', a more general word like 'singer' or 'musician' would do better.
I'm back home now, so I can pull my old (huge) Lewis and Short off the shelf. Here are the English equivalents it gives for "vates":
Original: a foreteller, seer, soothsayer, prophet
By transference: a poet, poetess
Post-Augustan: an oracle (i.e. a teacher, master, authority in any art or profession)
Even in 1879, they considered "bard" too archaic as a translation. :)