From LSWiki

Bonding Requirements

Looks like empathy is the main requirement, based on the failure message:

You sense that the black male panda bear feels as though you could use more affection and warmth in your life.

(One was successfully bonded with a buffed Empathy of 130 and not much else besides a couple of trains as a fresh human VV explorer)

Known Abilities

Combat Bonuses

Attribute Modifications

Specialty Bonuses

Bonus specialty degrees and access are provided as follows:

Charms

Shortly after bonding

• Standard Charms
• Tame
• Command

Somewhat frail

• Enable Darkvision

Additional Bonuses and Powers

Traits granted