No it is not Bid'ah... It is a description that carries a praise, which does not diminish the status of the Quran.
And Bid'ah cannot be loosely used everywhere like that. The classical scholars have defined Bid'ah to have two meanings: something that did not exist or was not done during the era of the Prophet (saw) endorsed by scholars like Shafi'i, Ibn Hazm, Nawawi, Qurafi and al-Izz al-Din ibn Abd al-Salam et al or something that opposes or clashes with the Qur'an or Sunnah stated by scholars like Shatibi, ibn Rajab al-Hanbali, Mullah Ali al-Qari al-Hanafi et al. In essence both are saying the same thing - anything not rooted in revelation is unacceptable.
Allah knows best