Given that Kindred is omnipresent and Ivern's very much aware of beings like Bard and Aurelion Sol, they're almost certainly aware of one another., though I couldn't say whether or not they've interacted with one another. Maybe in the event of him saving someone from certain death, such as in Gift of Venom, he might have seen them before, but that remains to be seen. I could imagine it, where Ivern's there to comfort a dying creature and meets Kindred that way. He'd perhaps end up reassuring the dying creature about it's ultimate fate and what will come after, so it can recieve Lamb's arrow, though that's me just speculating on whether Ivern'd be inclined to try and help beings die in a more peaceful manner so they'd recieve the sweet release of an arrow rather than the ripping and tearing of wolf's jaws.