Adding property to object from async operation in Rx.js

Question

Let's say I have a observable coming in, something like this below. Here, company has a method website. I'd like to add a new property to this object called websiteStatusCode that is a number. The value of websiteStatusCode the status code for the website. I have to make an HTTP request to the server and I want to store the status code. We have a request promise that returns response.statusCode.

companyStream.map(company => {
  // company.website
})

Do I simply open the promise within the map? Do I have to wrap the promise within a Rx.Observable.fromPromise and return that?

companyStream.map(company => {
  if (!company.website) {
    company.websiteStatusCode = false
    return company
  }
  return Rx.Observable.fromPromise(request(company.website).then(request => {
    company.websiteStatusCode = request.statusCode
    return company
  }))
})

Is this valid code above? Is there a better way to tap into object properties with Rx that's not so verbose?