Wiki Q&A

The supplied context does not contain any specific recommendation for spending points on Bonehorns. It only describes the general Taming Bestiary system: players earn up to 20 upgrade points, each class (Attack/Utility/Tank) has its own pool, and upgrades cost 1, 2, and 2 points for Tiers 1, 2, and 3 respectively [1][2]. You can optionally spend up to 5 points on Cross-Class upgrades [3]. Bonuses apply only in PvM and generally only to creatures of the same class [4]. No Bonehorn-specific upgrade advice is present in the supplied chunks.