All necessary stuff is available in the systemd overlay. http://git.overlays.gentoo.org/gitweb/?p=user/systemd.git;a=tree;f=net-wireless/bluez Reproducible: Always
AFAIR bluez supplies systemd units but with --with-systemdunitdir instead of --with-systemdsystemunitdir.
Created attachment 278093 [details, diff] Patch to add systemd unit file to net-wireless/bluez-4.94-r1 This includes a unit file. AFAICS bluez upstream doesn't provide any unit files, at least not in their git repository.
+*bluez-4.95-r1 (08 Jul 2011) +*bluez-4.95 (08 Jul 2011) + + 08 Jul 2011; Pacho Ramos <pacho@gentoo.org> -bluez-4.91.ebuild, + -bluez-4.94-r1.ebuild, +bluez-4.95.ebuild, +bluez-4.95-r1.ebuild: + Version bump, install systemd files (bug #371873 by Christoph Brill, Michał + Górny and Henry Gebhardt), RDEPEND on media-libs/libsndfile only with USE + 'alsa' (bug #373117 by XhE), remove old. +