I don't know if I'd include it directly since the bubble assets aren't part of the pack, but I can show you the properties I used:
For the farthest back bubbles, I use a small image and I have an AlphaMask to make sure they appear behind some of the midground and foreground elements. I use the following properties:
particle_size=8, xspeed=(-10, 10), yspeed=(-20, -10), yacceleration=(10, 20), flutter_width=(100, 200), flutter_xtime=(4, 8), damp_xflutter=-1.0,
For the midground bubbles:
xspeed=(-10, 10), yspeed=(-50, -30), yacceleration=(30, 40), flutter_width=(100, 200), flutter_xtime=(4, 8), damp_xflutter=-1.0, origin_points=[(400, 1.0), (1200, 1.0)],
And for the foreground bubbles:
xspeed=(-10, 10), yspeed=(-100, -40), yacceleration=(30, 40), flutter_width=(100, 200), flutter_xtime=(4, 8), origin_points=[(0.0, 1.0), (0.05, 1.0), (0.1, 1.0), (0.85, 1.0), (0.9, 1.0), (0.95, 1.0), (1.0, 1.0)],
As with the existing examples, it's most helpful if you have multiple layers where the farthest back layers move the slowest and have the most particles, and the foreground layers move the fastest with the fewest particles. I used origin points here to make it appear that there were particular places the bubbles were coming from, but you could also just let it start at the bottom of the screen depending on what your background looks like. The acceleration is good for an effect like this, to make the bubbles move faster as they rise.
Hope that helps!