Magento – Magento Product custom attribute options not showing up in admin

In my Magento ce 1.9.2.1 website, I have created many product custom attributes by setup-upgrade scripts like below:

<?php
$installer = new Mage_Eav_Model_Entity_Setup('core_setup');

$installer->startSetup();

$installer->addAttributeGroup('catalog_product', 'Business Directory', 'Business Directory', 1000);

$attribute_set_id = $installer->getAttributeSetId('catalog_product', 'Business Directory');

$attribute_group_id = $installer->getAttributeGroupId('catalog_product', $attribute_set_id, 'Business Directory');

$installer->addAttribute('catalog_product', 'city', array(
    'label'             => 'City',
    'type'              => 'varchar',
    'attribute_set'     => 'Business Directory',
    'input'             => 'select',
    'default'           => '',
    'backend'           => 'eav/entity_attribute_backend_array',
    'frontend'          => '',
    'source'            => '',
    'global'            => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_STORE,
    'visible'           => true,
    'required'          => false,
    'user_defined'      => true,
    'searchable'        => false,
    'filterable'        => '1',
    'comparable'        => false,
    'visible_on_front'  => false,
    'visible_in_advanced_search' => false,
    'unique'            => false,
    'option'     => array (
                        0 => array("Please Select City...")
                    ),
));

$installer->updateAttribute('catalog_product', 'city', 'is_filterable', 1);

$attribute_id = $installer->getAttributeId('catalog_product', 'city');

$installer->addAttributeToSet($entityTypeId = 'catalog_product', $attribute_set_id, $attribute_group_id, $attribute_id);

$installer->addAttribute('catalog_product', 'postcode', array(
    'label'             => 'Postcode',
    'type'              => 'varchar',
    'attribute_set'     => 'Business Directory',
    'input'             => 'select',
    'default'           => '',
    'backend'           => 'eav/entity_attribute_backend_array',
    'frontend'          => '',
    'source'            => '',
    'global'            => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_STORE,
    'visible'           => true,
    'required'          => false,
    'user_defined'      => true,
    'searchable'        => false,
    'filterable'        => '1',
    'comparable'        => false,
    'visible_on_front'  => false,
    'visible_in_advanced_search' => false,
    'unique'            => false,
    'option'     => array (
                        0 => array("Please Select Postcode...")
                    ),
));

$installer->updateAttribute('catalog_product', 'postcode', 'is_filterable', 1);

$attribute_id = $installer->getAttributeId('catalog_product', 'postcode');

$installer->addAttributeToSet($entityTypeId = 'catalog_product', $attribute_set_id, $attribute_group_id, $attribute_id);

$installer->endSetup();

unset($installer);

As you can see, both the attributes are select(dropdown) and both have no values initially when they are created(this is my custom key criteria, empty attributes dropdown only).

But when I populate them programmatically from frontend form, their values doesn't show up in Admin >> Catalog >> Attributes in their forms. They still show no options in admin, why ?