It should not, since the main ingredient is supposed to be cassava starch.  And many times they do place a plastic lid on the glass, but who can you really believe ?.  Nothing will surprise me in China, when some business owners will add harmful chemicals to baby milk powder to make more profits, and many other things we can read in the news almost every day.

I do not know, what is this? Is it like our tapioca pudding. This I like but we can't buy the large tapioca to make pudding. I used it in peach pie.

TedDBayer:  Pearl tea is like a milk tea with a bunch of round golden looking small balls at bottom of glass (and tasty too).  Quite common here in China.

Try http://www.google.com.hk/search?q=photo+of+pearl+tea&hl=zh-CN&newwindow=1&safe=strict&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=WckcT5GvI5GviQf-3qSeCw&ved=0CCYQsAQ&biw=1536&bih=751
to see photos of it

So true Happy and I would like to add toothpaste, milk, and a good deal of other items to the list.  Nonetheless, the Chinese react with fury when they learn these things.  It's just pure greed,

Lower the frequency of eatingout or sth like that as possible as you can, in China everyone knows that, and there's always something exceeding your expectation, which may demotivate you. In China the most delicious and the most safe dishes and cuisine are made within family who won't use bad ingredients which are cheaper to attain high profits.

I used to drink bubble milk tea every second day like a junkie until seeing a picture of the whole process of how it is made.I was in shock and swore never drink more than once in a month. Some make very nice flavour but the picture just won't stop hovering in my head.I still like the taste,though. I know I would try not to drink it for health's sake.And to answer your question, I'm more than sure that those sticky black sometimes brown "pearls" definitely contain plastics. 

https://www.politico.com/states/california/story/2020/05/22/california-environmentalists-fear-plastic-tableware-will-become-dining-norm-1285630

well damn, so much for environmental politically correct global warming plastic is evil agenda.  RIP. Cloth bags are being replaced again with plastic also.