I think graph builder can do what you're after. If you drag two variables together to the Y field you can via the contextual menues (right-click) add both a line and points and then set which variable that goes with each graph type.
A script example:
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
Graph Builder(
Variables( X( :name ), Y( :height ), Y( :weight, Position( 1 ) ) ),
Elements(
Points( X, Y( 1 )),
Line( X, Y( 2 ) )
)
)