the bloke came to stay with us was from Africa

we had this African bloke came to stay

there a guy in our class has a an ¡Phone

Does such omission commonly occur in written English?

1 The bloke (that) I spoke to was from Africa.

2 The guy (that) I saw in our class has an iPhone.

But if "who/which/that" stands for the subject, you cannot omit it in standard English.

3 The bloke who came to stay with us was from Africa.

4 There is a guy in our class who has an iPhone.

However, in some dialects it can be omitted when it is used as the subject. Your examples are from a dialect where this is possible.

Alienvoord

“But if "who/which/that" stands for the subject, you cannot omit it in standard English.”

I agree to a large extent. However, some writers do omit the relative even then. I remember a couple of sentences:

There's somebody at the door [who/that] wants to see you.

I don't remember who said/wrote that.

"All stories [that are] long enough end in death."

Ernest Hemingway

The last sentence may not qualify as a particularly good example as both the relative and the verb (are) have been omitted. (I've been thinking of using it as my signature one day, by the way.)

CB

Cool Breeze

“"All stories [that are] long enough end in death."

Ernest Hemingway”

Since the verb is omitted too, that's a different construction.

Then how about these?

All taking drugs will be prevented from participating.

All found guilty of drug abuse will be charged.

All entering must produce the correct papers.

All meeting Jim tomorrow can be sure of a good laugh.”

These are different constructions too. These sentences only have 1 clause each.

I found an example in a Michael Moorcock novel from 1976, in dialogue:

"Or maybe it was the bus company found out he hadn't paid his fare from Shepherd's Bush."