I tend to use the map notation for belongsTo, so I would do it like this:
class Status {
String text
static belongsTo = [author: Person]
}
Then you're query is easy:
def messages = Status.findAllByAuthor(currentPerson)
If you had bidirectional added into Person with hasMany:
class Person {
static hasMany = [messages: Status]
}
You could also do this:
def messages = currentPerson.messages