A bad transfer tests indicates that the drive used to perform the test has problems reading the disc. This might mean that other drives could also have problems.
A good transfer test indicates that the current drive, and probably other drives of the same model, can read the entire disc without having to re-read anything. It doesn't guarantee that the disc can be read in other drives, but it increases the likelihood of that.
What would really guarantee that a disc can be read for years to come?
That one is easy: Nothing, I repeat nothing, will guarantee that!
Using quality media and a burner capable of burning with good initial quality improves the chances. Storing the media properly also improves the chances. Burning the data onto multiple media of different origin also improves the chances. Scanning your media to detect early deterioration may increase the chances, but OTOH every time you handle a disc there is a small chance of damaging it.