Nope, this bug is still there in 1.8.1.8.
StarDock Devs: Check your merge status of the fix - remember, this fix is in a DLC, not the main game branch.
 
Also, for those who haven't figured out the formula for mapping Sensor Power to radius:
 
SP = (X+1)(X)/2
 
That is, the minimum SP necessary to have a radius X is the cumulative sum of X  ( 1 + 2 + 3 + ....  + (X-1) + X)
Solving the other way (i.e. given SP, find X):
 
X = (-1 + √(1+8*SP))/2
 
Changing the value from +2 to +12 seems reasonable, as it has the following effect:
- For ships with a starting Radius of 3 (the minimum), it gives a +3 Radius bonus
 
- For those with a starting Radius of 3 or 4, it gives a +2 Radius bonus.
 
- For those with a starting Radius of 5 to 8, it gives either a +1 or +2 Radius bonus, depending on the exact SensorPower before the bonus
 
- For those with a starting Radius of 9 to 11, it gives a +1 Radius bonus.
 
- For those with a starting Radius of 12 or more, it gives either NO or +1 Radius bonus, depending on the exact SensorPower before the bonus
 
 
Also, we should change the wording of the Event itself:
$ diff -c data/English/Text/DLC4_ColonizeEventText.xml data/English/Text/DLC4_ColonizeEventText.xml.fixed
*** data/English/Text/DLC4_ColonizeEventText.xml        2016-07-29 09:28:34.795471900 -0700
--- data/English/Text/DLC4_ColonizeEventText.xml.fixed  2016-08-07 00:19:38.000812000 -0700
***************
*** 260,266 ****
    <StringTable>
      <Label>PrecursorSatellitesEvent_Benevolent_Bonus_Dec</Label>
!     <String>+10 Benevolent, +2 Sensor range to all ships, and colonies.</String>
    </StringTable>
    <StringTable>
--- 260,266 ----
    <StringTable>
      <Label>PrecursorSatellitesEvent_Benevolent_Bonus_Dec</Label>
!     <String>+10 Benevolent, +12 Sensor Power to all ships and colonies.</String>
    </StringTable>
    <StringTable>