Recently, veteran officials that I have worked with, are saying that a "T" on the coach is not charged as a team foul counting towards the bonus rule. I believe that all fouls count towards the bonus rule. I cannot find any rule that states otherwise.

To answer your question....yes, a direct technical to the coach also counts
toward the team bonus (see rule 4-8-2, p. 27).

All T's in NF rules count towards the team foul bonus.

Yor are correct, Rule 4-8-2 states that: Player-Control fouls and technical fouls are counted as team fouls to reach the bonus. When a technical foul is also charged indirectly to the head coach, it counts only as one team foul.