What this really illustrates is that for many species there are differing times when root work can happen. But it depends on your ability to provide good aftercare and what place the tree is in it's development. So for us to say whether you can pot your tree is not terribly helpful sometimes... you have to know your tree, it's strength, and what your goals are for this year.
If the tree is getting seriously downsized or put into the pot for the first time and one has to really get after the roots... then flowers be hanged, skip a year of show and do it early spring.
If the roots aren't a big deal and the tree has been a bonsai for a while... post flower is fine.
If you want to have a really advanced year and have the space to stick it in a green house (assuming it has had a dormant period - ie. you are likely a professional grower)... then working on it in winter is not off the table either.
So whatever you do, you have to know your tree... I rarely pot a tree I haven't had for a year, unless I am very familiar with the species and I have some kind of clue as to when it was last root worked. Health isn't always an obvious indicator, just because a tree can be vigourous after a repot... but doing it two growing seasons in a row could piss it off.
So if the tree isn't in trouble and you are not sure... get to know the tree more and you'll have no room for regret.
Kindest regards,
Victrinia