Are the tiles for the tile collection awarded in a certain way based on number of points scored in the bonus game of Tiles? Or is it all random? I scored over 5k points and haven't finished that many bonus games to figure out a pattern.

Thank you!

There is definitely a pattern. I've tried working it out and can't because I don't play enough. I've collected some data: Tiles - Wooden Tiles. There is a link to a very old thread in there that I have no idea if it still applies or not.