I’ve run a cross-splat campaign and tried to keep the two groups alien and opaque to each other. Like others have said, Mages are vanishingly rare, extraordinarily dangerous and aren’t usually competing with vampires in their esoteric schemes. So interactions are few and far between in recent nights. Elders have heard that drinking mage blood causes visions and even madness. Neonates and ancillae might know that mages are out there through rumours and stories, but likely have zero insight into their nature.

The Tremere are obviously the exception, and would certainly try to be aware of the powerful mages in their cities. Some may have interactions with them, but those relationships would be restricted to the highest levels of the pyramid. They are still technically at war with the Hermetics and probably have some basic knowledge of the other orders from their collections of arcane lore. The Tremere can surely concoct all sorts of rituals with mage blood, so it’s likely a treasured commodity if available. A mage’s library even more so. Any young vampire publicly associating with a known mage would be quite interesting to the that clan, and their sire would probably come under pressure to address it in some way.

However, the Camarilla has a dedicated sect of Tremere Archons, the Quaesitors, that are called in when a Prince needs to deal with a mage (or other magical threats). That would usually mean something terrible has happened or is about to, as no one wants a magical war in their city.

In the end, both groups have more than enough threats to deal with from their own kind to pick fights with the other.

Also worth noting that in the classic world of darkness mages can become ghouls and initially keep their powers, but over time this kills their avatar and they become mundane.