Pal trust maxes out at Level 10, so once you’ve reached that threshold, ... However, Pals can also get a big boost to trust when they eat a Kinship Peach. How to get Kinship Peaches.

This legendary fruit will instantly boost the Trust of a Pal by multiple levels. Kinship Peach is a rare item and can be found randomly in gold chests or exchanged for 15 bounty tokens.