Hello Peter.
Yes, dogwood air layer, you should get roots in less than 4 months after putting the layer in place.
Flowering dogwood, of which this is clearly a member of that group, they are used for bonsai occasionally and when they are used they can be absolutely stunning in bloom. They are a little '"tricky". They tend to have long internodes between leaves. Not inevitable, but it is a tendency.
Most often flowering dogwood is used as a deciduous "literati like" style. Or in a manner to mimic the loose airy designs of Ikebana designs. So rather than a tight, informal upright like one might make with a crab apple. Go for a design that is loose and airy, long slender trunks with attractive movement and relative little in the way of branch development. Bill Valavanis has displayed a flowering dogwood he owns several times. Check his blog at International bonsai.
THe only photo I found in my "examples file" is not at all like I described. It is also by Bill Valavanis, and is done in a more conventional informal upright. The photo belongs to Bill Valavanis, from an article he published in 2014.
