As this is a structure subject to load cycling I would look to examples of how aluminum masts and wings are constructed.
Bonding aluminum sections with adhesive will need to be flexible and spread over an unknown minimum area.
If the seam is perpendicular to the compression/tension vector without creating a stress concentration in the mast is unlikely. Also there is a risk of cold temperature bond failure if you sail in high latitudes.
For a freestanding mast intended for offshore sailing this is what I would look at making.
An all alloy 6061 structure with a composite join comprised of the two sections, a riveted inner sleeve to fix them in place and welding to fix permanently.
Several plug welds above and below the seam
A butt weld around the seam. Weld in alternating sides of the tube structure in small 1 inch segments to prevent mast centerline deviation. Any deviation can be corrected by alternately using a weed burner and a water hose to straighten it.
If the mast is for inshore sailing then riveting (with several more rivets) would suffice.
This is over-engineered, more expensive and takes more time.
Getting back home after a mast failure will be well . . You know...
RC