I wouldn't like to press your luck. I doubt airlines vary much in these matters, and standing at the check in counter is a very bad place to find it out.
Virgin/pac Blue are like this, Air NZ too. Qantas are and always have been sods when it comes to baggage....
It is like $55 to book an extra item of luggage up to 23kg. If you do not book it, you will be hit for....I think excess baggage weights for every kilo of that extra item. On a 4kg rod tube to Aussie, that was $80! Way cheaper AND easier to simply book the extra bag, then you can cram it full of stuff as well, just in case your luggage is getting a bit close to weight (like mine always is) If you wrap them well, you can then pop really heavy stuff, like jigs, into your rod tube as well, as long as they do not crunch your rods.... gives you a spare 23kg of fishing gear you can take with you! ;-) hell that is nigh on another 60 jigs, and in Vanuatu you will need them! :-)