It's reasonable that your dictionary doesn't have the reading まとわる since まとわる is not used nowadays. Especially, for the meaning "to be related to~/concerning~", only まつわる is used, and まとわる is never used for this meaning.
This is a bit confusing, but 纏う is まとう, and まつう is obsolete. The same goes with まとわす vs. まつわす. まとわす is common, and まつわす is not used. (This is because まとわす is originally from the classical causative form of まとう.)
As for まとわりつく, although it's indeed the combine verb of まとわる and つく, many dictionaries has the entry of this word now. You can think it's used like a single verb.
According to NHK's research in 2014, over 80% of people only use まとわりつく, and never use まつわりつく. Then, NHK changed their domestic rules for broadcasting from the previous one "both まつわりつく and まとわりつく are equally recommended" to the new one "まとわりつく is the primary reading" in 2018.
In conclusion, it's safe to use the following readings.
まとう
まとわす
まつわる
まとわりつく