Reading Terminal is a big marketplace. They will only card you at the places that serve alcohol.
They won't serve you at the bar, but you'll be fine everywhere else.
If they serve you alcohol without checking your ID and you look like you're younger than 21 I would assume they would be breaking the law So my answer that question would yes.
None checks id to go in the market. I am not sure there us anywhere inside market where you get alcohol.
Thanks! Your answer is awaiting moderation.