>>46609831I should throw out that NONE of these require the creature to be able to speak a human language or understand a human language. You can be Sapient and Sophont while only speaking your language, its all about what's being said in that language that defines it.
If when two pokemon are having a conversation its wise and intelligible to one another they are Sapient. If the conversation is complex and intelligent to Human level communication they are also Sophont. Unfortunately the only amount of proof we have for Pokemon/Pokemon communication is from the anime and with Rotom. I know we've had moments where TR's Meowth has had complex Sophont level conversations with other wild and non wild Pokemon who also seem to fully understand him, so in the Anime I'd argue most if not all Pokemon are Sophont. In the games I can't recall a moment where Rotom translates for another Pokemon or if another Pokemon holds a conversation with another Pokemon we can understand, so here its technically up in the air.