docker.sls

# foo-docker-app.sls (state)
{% set app = salt['pillar.get']('docker-apps:foo', {}) %}
{% if app %}
[...]
{{ app.name }}-service:
  docker.running:
    - name: {{ app.name }}
    - container: {{ app.name }}
    - port_bindings:
      {{ app.port_bindings }}
    - require:
      - docker: {{ app.name }}-container
    - watch:
      - docker: {{ app.name }}-container
[...]
{% endif %}

# -----
# docker-apps.sls (pillar)

docker-apps:
  foo:
    name: foo
    iname: bar/foo
    tag: latest
    port_bindings: |
      "80/tcp":
        HostIp: ""
        HostPort: "8001"

add this before the if statement:
{% set portbinding = salt['pillar.get']('docker-apps:foo:port_bindings'; {}) %}
replace {{ app.port_bindings }} with {{ portbinding }}
that should do the trick, although I haven't tested it..

another option would be to
{% set app = salt['pillar.get']('docker-apps:foo', {}).items %}
this way (might need some tweaking thought, again, i'm not testing anything) you should be able to access everything in your pillar with app.get('name'), app.get('iname') etc