what size pot - really dumb question

[ladyslipper]

Hi guys, this might seem really obvious but I am not clear about the answer...at the moment, I am growing phals (both species & hybrids) and my amabilis needs to be repotted. the vendor said to just replace the medium, & said the pot size was fine. This plant looks like its trying to climb out of the pot. So how do we know when to bump up the size of the pot? Are we supposed to know which of our plants like to have their "feet" cramped?

thanks m