Bishops are to consult experts in art, so Vatican II says:
When passing judgment on works of art, local ordinaries shall give a hearing to the diocesan commission on sacred art and, if needed, also to others who are especially expert, and to the commissions referred to in Art. 44, 45, and 46.
Bishops are ultimately responsible for altars, pulpits, and other major aspects of churches in their diocese:
Ordinaries must be very careful to see that sacred furnishings and works of value are not disposed of or dispersed; for they are the ornaments of the house of God.