You need an AM account for the SPG transfer. You cannot upgrade on CX with AMEX points.

The only way you're going to upgrade an award ticket, if it was secured with AA miles as a partner award, is to reticket and spend more miles.

The Cathay experts here will be of more help on the paid ticket, but it sounds like you have no Asia Miles to use for an upgrade. One of the previous posters suggested transferring SPG points into Asia Miles.

OK, I opened AM account and figured out how to transfer spg points. But then do I call AM or Cathay to upgrade with miles? Is it guaranteed award or still pending clearance? Will I know right away?

Is it possible to upgrade award ticket with Asia Miles?

Was the award ticket purchased with AA miles? If so, you'll have to reticket and spend more AA miles for a higher class of service.

Didn't you say you had no Asia Miles or even an account?

If you have an AA award, there is no hope of getting into J unless you pay for the difference in cash.

If you have an Asia Miles award, you can refund the ticket and rebook yourself in a J award subject to you paying the refund penalty and there is award availability.

I tried locating a thread on such topic but could not. Here is a summary on upgrade on CX (economy to business):
* There are two phases: booking and confirming.
* The underlying ticket must be in booking class Y, B, H or K.
* Upgrade can only be done with Asia Miles.
* Booking an upgrade is subject to upgrade seat availability, unless you have certain MPC status (e.g., a DM can easily get an upgrade unless the flight is getting full). CX may release seats over time, sometimes in the few days before departure. And sometimes you may know if your upgrade is availability immediately when you book.
* Transfer from SPG to Asia Miles takes time, from several days to several weeks. The fastest I encountered was four days in my recollection (probably a record), but that can take up to six weeks.
* You must have Asia Miles and the underlying ticket to confirm the upgrade, and the Asia Miles must be in the account already (or at least 70% if you intend to top off).
* You must confirm the upgrade before the ticketing deadline.

I don't think you can even pay the "difference". You will need to buy a new J ticket to sit in J if you are currently holding a Y ticket issued by AA award.

Or change the class of service of the award ticket (assuming it's AA) by reticketing with the higher mileage amount.

* The underlying ticket must be in booking class Y, B, H or K.
 

Well, this pretty much asnwered the questions - I am booked in L class, so don't qualify for an upgrade. Oh well, it is what it is! :)

I was surprised that award ticked was only 25K.

There's always op-ups, which CX isn't as conservative in as SQ. See http://www.flyertalk.com/forum/11220620-post9.html

Even as GR (base level, no elite status), I've had an op-up for JFK-HKG once and a few others have too...so AA Gold does have a chance

:)

An OP on JFK-YVR-JFK is the least likely route in the whole CX Network its rarely Half Full..as the bulk of the HKG Passengers are uplifted at YVR.

I've been op-up'd about 6-7 times between JFK-YVR since 2005 -- 3x in the last year alone (as an AA EXP/Emerald).

Happened twice as a PLT/Sapphire as well....about 3 yrs ago.

Usually happened on full flights around holidays.