What schema for different relation from two tables to another?
Rearranging / rephrasing your relationships a bit:


1 instructor has 0, 1 or n meeting_points.
1 meeting_point is linked to 1 instructor.

This means there is a simple 1:n (1::0-n) relationship between them. The foreign key should be in meeting_points, referencing instructors.
1 booking has 1 meeting_point.
1 meeting_point is linked to 0 or 1 booking.

This means there is a simple 1:1 (1::0-1) relationship between them. The foreign key should be in bookings, referencing meeting_points.
There are no direct relationships between instructors and bookings.  

The implementing is obvious here.


Without further information about other attributes and possible unique keys, I'll use the above, adding surrogate unique keys in the first two tables (this is not needed, the surrogate keys could be replaced by other unique keys you may have identified). The bookings table does not need a surrogate anyway, as it's in a 1:1 relationship with meeting_points and the same column can be used as primary key and for the foreign key constraint:

CREATE TABLE instructors 
(   instructor_id SERIAL NOT NULL,
    instructor_name TEXT NOT NULL,
    -- other attributes
    PRIMARY KEY (instructor_id)
);

CREATE TABLE meeting_points 
(   meeting_point_id SERIAL NOT NULL,
    meeting_point_name TEXT NOT NULL,
    -- other attributes
    instructor_id INT NOT NULL,
    PRIMARY KEY (meeting_point_id),
    FOREIGN KEY (instructor_id)
        REFERENCES instructors (instructor_id)
);

CREATE TABLE bookings 
(   booking_id INT NOT NULL,
    booking_date DATE NOT NULL,
    -- other attributes
    PRIMARY KEY (booking_id),
    FOREIGN KEY (booking_id)
        REFERENCES meeting_points (meeting_point_id)
);


Sidenote: The relationship "a meeting_point has (max) one booking" does not sound very realistic. So, if A is an instructor and M is a meeting_point, A can only make one booking in M? What if she wants to make another booking in the same point tomorrow? This would not be allowed under this design.