filter over a promise Emberjs

I'm trying to create a search coming from a JSON API. I have seen a few tutorials teaching how to do this and I got it working with their examples:

export default Ember.ArrayController.extend({
    searchText: null,

    searchResults: function(){
            var searchText = this.get('searchText');

            if ( ! searchText)
            {
                return;
            }
            else
            {
                var regex = new RegExp(searchText, 'i');
                return ['hey', 'dude'].filter(function(c){
                    return c.match(regex);
                });
            }
        }.property('searchText')

});

This works great however when I try to do the same with a promise I get lost:

export default Ember.ArrayController.extend({
    searchText: null,

    searchResults: function(){
            var searchText = this.get('searchText');
            var adapter = AddressBookAdapter.create();
            var companies =  adapter.findAll();

            if ( ! searchText)
            {
                return;
            }
            else
            {
                var regex = new RegExp(searchText, 'i');
                return companies.filter(function(c){
                    return c.match(regex);
                });
            }
        }.property('searchText')

});

Here is the adapter class:

export default Ember.Object.extend({
    findAll: function(){
        return ajax('http://localhost:8000/api/v1/address-book/companies')
            .then(function(response){
                return response.data;
            });
    }
});

here is an example of the JSON API response structure:

{
  data: [
    {
      id: 6,
      name: "Alexandrine Skiles",
      links: [
        {
          rel: "self",
          uri: "/api/v1/address-book/alexandrine-skiles"
        }
      ]
    },
    {
      id: 33,
      name: "Ally Johns",
      links: [
        {
          rel: "self",
          uri: "/api/v1/address-book/ally-johns"
        }
      ]
    }
  ]
}

I get this error:

Uncaught TypeError: companies.filter is not a function

I tried figuring out a way to convert a promise into an array so I can run the filter function but came up with nothing. What is the correct way to achieve what I am trying to do?