Try naming your red line layer "Red Line" and using this expression for scale on a text layer:
t = length(position, thisComp.layer("Red line").position);
s = ease(t, 200, 0, 150, 100);
[s, s]
The Length method is under the Vector Math section of the expression language menu, the ease method is under the Interpolation section.
You are measuring the length between the anchor point of the current layer and the anchor point of the Red Line layer. Then a simple interpolation method takes the length ("t" for temporary value of length) and applies an ease when t starts at 200 and ending at zero between 150 and 100. The result of the interpolation method translates to scale for the layer with the expression.
For this to work properly the text layers should be created with the anchor point directly in the center of the text in a center justified paragraph. You can easily center the anchor point by using the baseline shift property in the Character Panel. Start by using the resetting the position of any text layer you created by clicking with the type tool anywhere in the comp panel and typing, then match the baseline shift for every layer.
That should do it.