It's quite likely that once you return your bird will have gone backwards in his training, just because there was a long gap where you didn't work with him. Just be sure to take things one step at a time with him, and if need be go back a step in his training once you return to ensure he's comfortable before moving on to the next step. I wouldn't be too worried. Once you get back and you can begin working with him regularly and he should begin to trust you more.
If your going through actual training techniques with him there may be a little regression but there's no way he will forget you in two weeks. As you don't have a strong bond yet this shouldn't be a problem.
Your budgie hasn't been with you long enough to have formed a lasting bond with you at this time.
When you return, you'll need to start over with the taming and bonding sessions from the very beginning to work on building his trust.
Enjoy your vacation and you can start a new thread on Taming and Bonding with Kamil after you return.