Congrats on taking two SAT subject tests and scoring so well on them!! This is a major achievement and you should be so proud of yourself for doing so well. When I was applying to college many of the schools heavily recommended that I take SAT subject tests and submit their score. SAT subject tests show that you are willing and able to go beyond what is expected and put in that extra effort. While not a gold ticket into university, sending SAT subject test scores can only help you. NOTE, that you likely want to only submit the scores that you do well on to highlight your academic abilities; submitting a 360 would not help you and actually may hurt you depending on the school that you are sending these scores to.
I was always told to send scores above 700 but honestly your 690 is close enough!! Even if your school doesn't require them, additional test only help set you apart from everyone else who is applying.
I hope this helps and I wish you the best of luck!!