You need to have a clean 7.0 Stock Rom to receive and install the latest 7.1.1 OTA. Because there is no Stock 7 available for reteu, here's what i did:
Flashed this version: XT1650-03_GRIFFIN_RETBR_NPL25.86-30_cid50_subsidy-DEFAULT_regulatory-DEFAULT...
using RSD-lite (download/install on your windows pc)
https://my.pcloud.com/publink/show?code=mWertalK
Download the above mentioned Stock RETBR to your pc, unzip it and search for flashfile.xml.
Copy the flashfile.xml, so you'll get a flashfile-copy.xml.
Open the flashfile-copy with any text editor and delete the lines with "bootloader" and "gptbin". After that click safe.
Open RSD-lite program on your computer.
Click the 3dots right beneath the Filename.
Search your modified flashfile-copy.xml and double click.
Now put your moto z in bootloader mode and connect it with your pc.
Your device shows up in line 1. Click the Start button of RSD-lite.
The StockRom will be flashed onto your device. Wait, until your phone reboots completely and RSD-lite gives you a "PASS" under results. Then disconnect your device from pc.
Now you are on clean stock 7.0 (januar patch) and will receive several OTA's one after another.
With this clean system you'll probably get the latest 7.1.1 OTA.
There might be an easier way to reach the same, but thats what i did and it works.
Edit: After you have installed the 7.1.1 OTA be aware, that there is probably no way back to 7.0. I think until now, nobody has catched this OTA, so we don't have a backup for Stock 7.1.1 Reteu. There are dozends of MotoG4/Plus users bricking their devices by rolling back from version 14-8 to 14-4 because the bootloader was updated.