The answer is YES. Any work performed within the construction industry is covered by the CoInvest scheme providing it falls within the scopes described in Appendix A of the CoInvest Rules
Have a look at this page: https://www.coinvest.com.au/employers/trades-covered-by-the-scheme
If you drill down in the CoInvest Rules, Appendix A - Building Trades Work, Classifications then you will find "Spotter" specifically mentioned as #49 as a sub-category of "Labourer / Trades Assistant" (Page 75)
You will also find "Traffic controller (including, but not limited to, an attenuated driver)" as #58
Note however that the scheme covers only workers who perform more than five days of covered work within a month. This is relevant for casual workers.
More information is here on the CoInvest website: https://www.coinvest.com.au/