〜ともなると 〜ともなれば
Usage
「-という特別な状況や立場の場合は」when it comes to ~; if it reaches the stage of ~ (then naturally…); used to express that once a certain level or situation is reached, something is to be expected
Examples
首相ともなると、気軽に自由な行動はできない
Once you become prime minister, you can’t act freely and casually.
結婚して50年ともなると、顔を見るだけで相手の気持ちがわかる。
After being married for 50 years, you can understand your partner’s feelings just by looking at their face.