I formerly went to Lollicup in Super 88 to get my Bubble Tea fix, but I'm now a devotee of Infusions Tea Spa on Brighton Ave in Allston. The jen ju coconut black milk tea is amazing-- far better than the artifical tasting tea drinks at Lollicup. The tapioca pearls are markedly better, as well.
For just over $4 you can add an order of "brick toast" spread with strawberry jam, peanut butter, chocolate, or garlic. It makes a pleasant and inexpensive snack. They also sell tea eggs, which I haven't been brave enough to try yet.
There is an Asian Bakery next door that seems to be owned by the same people-- it's worth checking out.