Art looks good to me!
I get bubbles now and then, and Im not convinced of the reason. Some say its the milk, some says its the espresso, some say its the water you brew espresso with.
One technique I read on this forum, is when you're about to pour the art:
Pour a bit of milk into the cup
Swirl the cup like you would a pitcher of steaming milk.
Pour your art.
Ive had some some good experience with this, but it doesnt work all the time.
When making a milk drink, what gives me the least amount/no bubbles, is pouring a shot from a spouted PF.