CLUSTER not in multi-command string?

ERROR:  CLUSTER cannot be executed from a function or multi-command
string

I got this error from a script which tried:
psql -U postgres db1 -c 'cluster ; analyze'

In the docs there's no word that it's not possible, and I wonder why
this is not allowed. Anybody knows? It's stupid, as I want to cluster
lots of tables, followed by analyze, and now I have to
psql -U postgres db1 -c 'cluster'
psql -U postgres db1 -c 'analyze'

mfg zmi
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