Bucket not available in Perch for uploading

I have created a content region which contains the following line among others:

<img src="<perch:content id="image" type="image" bucket="People" />" alt="<perch:content id="name" type="text" label="Name" />"/>

As expected, in Perch admin the first time I go to the relevant page > content region, this bucket folder is created on the file system. However, when I attempt to upload an asset to this content region, this bucket is never made available in the list of buckets to upload to.

I have deleted the folder from the file system, have seen it be created again, logged out and back into perch and still the same.

Is anyone able to shed any light on this?

Can I confirm, if I create buckets this way i.e. by just listing them in the content file, should this be sufficient to allow me to upload to them, or do I need to explicitly add them in the buckets.php file?

Thanks