Get points for a map of a promise and show them in the render

I'm trying to show the data that comes from a promise getTiendas in the const that defines the GoogleMaps markers but I'm not making it, what is wrong?

import React from 'react';
import AppBar from 'material-ui/AppBar';
import IconButton from 'material-ui/IconButton';
import NavigationClose from 'material-ui/svg-icons/navigation/close';
import NavBar from '../../components/NavBar';
import { withScriptjs, withGoogleMap, GoogleMap, Marker, InfoWindow, } from "react-google-maps"
const { compose, withProps, withStateHandlers } = require("recompose");
import { API_ROOT } from '../../config/api-config';

let getTiendas = new Promise((resolve, reject) => {
  fetch('${API_ROOT}/map/')
          .then(result => result.json())
          .then(res => {
            if (res.success) {
              resolve(res.data);
            }else{
              reject('Ha ocurrido un problema, intenta mas tarde.');
            }
      });
});


const MyMapComponent = compose(
  withStateHandlers(() => ({
    isOpen: false,
  }), {
    onToggleOpen: ({ isOpen }) => () => ({
      isOpen: !isOpen,
    })
  }),
  withScriptjs,
  withGoogleMap
)(props =>

  <GoogleMap
    defaultZoom={4}
    defaultCenter={{ lat: 19.432608, lng: -99.133209 }}
  >


{getTiendas.then((data) => {
  <Marker
    position={{ lat: 20.666667, lng: -103.333333 }}
    onClick={props.onToggleOpen}
  >
    {props.isOpen && <InfoWindow onCloseClick={props.onToggleOpen}>
      <span></span>
    </InfoWindow>}
  </Marker>
})}




  </GoogleMap>
);