The following two screenshots are from the same game, in one I have my strike cruiser selected in the other a gladius.
The shield upgrade is on the cruiser but not the escort when the tool tip says it applies to all ships. It's unclear if the effect is on the escort ship but the icon in it's details page isn't displaying, or if it is just not on the escorts at all.
0_1544324768202_Screenshot (24).png 0_1544324780590_Screenshot (25).png