The helpful table linked by @Paddy raises an important question: What constitutes a proclamation coin?
As I see it, the term has been used in at least four ways:
1. To refer to not only the coins in Governor King's 1800 proclamation, but also those that derive their face value from them: A halfpenny, half-guinea etc. Without the shadow of a doubt these would have been in circulation at the time. For better or worse, though, King includes a half-Johanna, which itself is a derived value. This suggests that sixpences etc were not "officially" accepted tender, but may have lead to some confusion on the matter in colonial practice.
2. To refer to early Australian colonial currency constitutes. This is unquestionably a misnomer. That would be like saying that every animal on the farm is a cow. There is a substantial body of anecdotal evidence that other specie, particularly bullion, were widely circulated and accepted. This doesn't mean that they were official currency, or even legal currency.
3. To refer to coins that constituted the official currency of the antipodean colonies only. There were were twelve similar decrees between 1788 and 1825. I see no reason why this is not a valid descriptor.
4. To refer to the 1800 Proclamation by King alone. This is a very narrow meaning and possibly needs further clarification when used.
My nascent collection (at this stage consisting of the guinea alone) is limited by the fourth definition at this stage, for reasons that I shall elaborate upon in a future post.
For further reading, take a look at this article *here*. On this page they're plugging a book that I recently purchased, "The Coinage of Colonial Australia" by Andrew Crellin. I'll post a book review some time in the next couple of weeks.