Is reading the Qur’an collectively before the Dhuhr and Asr prayers a Sunnah or a Bid’ah?

There is no harm in regularly attending a Quran recitation circle at a specific time, whether in the mosque or elsewhere, provided that no special virtue is attributed specifically to gathering for recitation at this particular time. The Companions used to gather and listen to a reciter among them, as the Prophet, peace and blessings be upon him, did with the People of Suffah, and as Umar ibn al-Khattab asked Abu Musa to remind them of their Lord through recitation.