Hi, I’ll try and do a breakdown to help.
120k Amex points = 90k Asia Miles
The distance from PER to HGK is 3754 miles.
The distance from HGK is 6388 miles.
3754+6388 = 10142 miles
https://www.asiamiles.com/am/en/redeem/charts
I don’t know to much about Asia miles but from what I’m seeing it looks like companion business fares are some of the best value I’ve seen in terms of what you can get for the amount of miles used, Please can others correct me if I get any of this information below wrong.
But from what I understand…
Unfortuanly the journey from Perth-Hong Kong- Vancouver ends up being Just into zone F. On a companion business fare you would need 120k Asia miles for this return trip. Which is 160k Amex points.
if you can somehow shorten the trip squeeze under the 10k mile threshold you and your wife would only be looking at 95k Asia miles which is not much more needed to be collected to what you could have with Amex points to Asia Miles transfer.
Going from Singapore or Bangkok to Vancouver with Cathay will have you land in zone E, so you could get the companion fare after a earning just a few thousand more Amex points to convert to Asia miles to get you to the 95k required.
Asia miles are excellent value in return trips but are more expensive one way.
A suggestion would be try and score a cheaper companion class fare with Thai Airways to Bangkok & pay with cash as they frequently pop up. Then use the Asia miles from there to Vancouver via Hong Kong with Cathay
or outright buy business class seats with Singapore airlines & do it from Singapore .
I have purchased them for just below $2k per person return before with Singapore Airlines.
Flying from Perth to Singapore myself pretty much every 2 weeks. Economy class tickets can be so super cheap, maybe you could score of some them and have extra spending money for nicer accomodation. upto you as it’s your trip 
but if you demand business class, well to Singapore on Singapore Airlines you would need 55k KrisFlyer miles per person & around $600 per person for taxes for a return trip, you can achieve KrisFlyer miles by converting your Velocity miles.
-note there is no point in upgrading purchased economy tickets with Singapore. Also not much point in redeeming economy fares with Singapore either. (Poor value as taxes are a killer for redeeemed economy flights and only expensive fully flex fares are upgradeble) Outright purchased economy or business fares can often be reasonably priced.
For Business return from Perth to Singapore you would need 110k KrisFlyer miles, x by 1.35 = 148.5k Velocity miles, that’s how many velocity miles you need to transfer to KrisFlyer to make this redemption possible, + around $1200 cash for surcharges. It may be a better option just to purchase business or economy tickets outright with Singapore or Thai & credit the miles earnt to KrisFlyer accounts or Virgin Velocity account (but only possible if the flights are travelled with on Singapore)
there are so many ways to skin this cat. You can purchase tickets and upgrade with Cathay, there’s other ways via Etihad, there’s too many scenarios to go through.
If you can’t come up with many more Velocity, Amex points or Asia miles quickly to open up your options more, then again my suggestion is try and redeem the flights from Singapore or Bangkok to Vancouver with Cathay from your Amex points converted to Asia miles, in a companion business fare zone E. + just pay your way from Perth to Singapore or Bangkok in whatever fare class you desire.
Hopefully some others can have some feedback and imput into this question for you as they may have better ideas as I’m sure everyone is going to wish the best value for your travels.
Regards, Kyall
