Does optusnet upload count toward you monthly quota?

Yes it does:

According to their terms and conditions:

* Data usage will be counted in Megabytes (MB) and includes both uploads and downloads. If you exceed your monthly data allowance, access will be speed limited to 64 or 128kbps depending on your plan until the end of the billing month.

References

This was found at:

http://personal.optus.com.au/web/ocaportal.portal?_nfpb=true&_pageLabel=Template_woRHS&FP=/personal/asadvertised/greatbroadbanddeal&site=personal