These seem like soothsayers, rather than bards.
Agree. Soothsayers is a better definition.
A bard strictly speaking is a poet. In the context of Rome, bards would be a foreign Gaulish and Brythonic (or 'Celtic') phenomenon. Moreover, ancient bards did not read, valuing the power of memory. '
It is often said that Gaulish couldn't read. (but I don't know to what extend it is true as the Gaulish alphabet did exist)
Bards are about oral traditions, like druids.
Some Gaulish here: http://www.antimoon.com/forum/t7315.htm