I am using Metric and want to type text to export as a STL for my 3D Printer. Is there a method of knowing or setting up the text size in points (pt)? In all other programs I select the size and know that I need a size of say 155, how can I do this in Blender? The scale I have as 1.000 if that's correct?
No, there is no way to set the size of a text object in points.
A point is just another unit of measure (wikipedia), so if you know the size point that your other programs and printer are using then you can set the size in blender. Typically a point is 1/72 of a inch or 0.3515mm. So for your 155pt you could set the size to be 54.4825mm.
The quickest way to do so would be to first, set the units to be Metric.
Then in the Properties panel, N to show it. Type in
54.4825mm to the Y axis. Copy the scale from the Y axis to the X and Z axes. The text is now sized at 155pt.