Ah. Even at a distance, they can hear each other - mind, and verbally. Tidus feels embarrassed for a split second, but then, more earnestly:

"We'll ask when we get back, once the train's right again. You've helped us save worlds - we've been in wars before. The least we can do is help your friends too."

As long as she wanted to try, then why shouldn't they? He was always adamant they should be helping the passengers too.