The pineal gland is in the mid brain and the 3rd eye chakra point is in-between the two eyebrows up slightly.
Why the distinction and which one would you focus on?
For intent, for de-calcification, for awakening and opening?
The seat of the Soul is seen in Hindu as being where the third eye is described to be. As we call the two side of our heads beside the eyes ... The Temples!
Every time you do your Inner Work, Meditation etc you will be energising your third Eye, and it is the enlightening means by which you are in touch with In-tution. Your entire inner landscape is viewed by the 3rd Eye. Your consciousness!
ANd it depends on how much Consciousness you have 'Awake'. It is said by the Masters that most human beings only have 3% consciousness awake!
The more you listen to your Intuition, meditate, and diminish the Ego, the more consciousness you will release.
I would recommend, that you meditate and work on all your energy centres.... the lower chakra's are vitally important, and you need a good foundation.
I recommend the Middle Pillar - is the most complete practice for awakening energy centres and working on chakra's.