I am no longer living in VN, but can understand your concern.
As I understand matters the regulations & their application remain 'fluid' to say the least!
In the absence of your having received any advice to date, may I suggest you consider contacting Flamingo Travel & see if they can advise & assist you for a fee.
If so the charge will be more than reasonable & you'll be secure in knowing you will have the correct documentation for yourself & your bike to ensure you can cross into VN.