Question

How is the amount of BP your receive determined in the PWT?

Answer 1

Battle Points will be awarded for winning a tournament. If the player loses, a shard will be given as a consolation prize. Battle Points vary depending on the tournament and performance.

Here is a table of the amount of Battle Points that are awarded for each Tournament and Battle Type:

Note: The World Leaders and Champions Tournament range from three onward because players are awarded one BP for every Pokémon that did not faint throughout the entire Tournament.

Source

Answer 2

It depends of what format of battle you are playing, who you battled(defeating gym leaders and champions gets you more) and your perfomance.

The source tells you in more detail.

Source

Go straight to "Battle Points".

Hope I helped!