I have a simple Jenkins job called "myjob":

Repository URL: git://github.com/jenkinsci/git-client-plugin.git
Branches to build: tests/getSubmodules
Build Triggers > Poll SCM is enabled

I execute

curl -s http://myjenkinssrv/jenkins/git/notifyCommit -d url=git://github.com/jenkinsci/git-client-plugin.git -d branches=tests/getSubmodules

and I get

No git jobs using repository: git://github.com/jenkinsci/git-client-plugin.git and branches: tests/getSubmodules

This is wrong! If I configure my job with "Branches to build"=master and call

curl -s http://myjenkinssrv/jenkins/git/notifyCommit -d url=git://github.com/jenkinsci/git-client-plugin.git -d branches=master

it works, as expected.