Unable to get expected speed up with cython (search in a list of strings)

I am unable to speed up computations with my cythonized version of a function bulk_phone_finder defined below (that uses phonenumbers pypi library) to :

from phonenumbers import PhoneNumberMatcher
from phonenumbers.phonenumberutil import SUPPORTED_REGIONS

def bulk_phone_finder(l):
    return [get_phonenumbers(content) for content in l]

def get_phonenumbers(content):
    return set([m.raw_string for cc in SUPPORTED_REGIONS for m in PhoneNumberMatcher(content,
 cc)
            ])

I am a bit new to cython , but i managed to make a cython equivalent function :

# cython: c_string_type=unicode, c_string_encoding=utf8
from phonenumbers import PhoneNumberMatcher
from phonenumbers.phonenumberutil import SUPPORTED_REGIONS
from libcpp.vector cimport vector
from libcpp.string cimport string
from libcpp.set cimport set as c_set


cpdef c_set[string] _SUPPORTED_REGIONS = SUPPORTED_REGIONS

cdef get_phonenumbers(string content):
    res = set()
    cdef string cc
    cdef string raw_string
    for cc in _SUPPORTED_REGIONS :
        for m in PhoneNumberMatcher(content, cc):
            raw_string = m.raw_string
            res.add(raw_string)
    return res


def bulk_phone_finder(l):
    res=[]
    cpdef c_set[string] int_res
    cpdef string content
    for content in l :
        int_res= get_phonenumbers(content)
        res.append(int_res)
    return res

this cython .pyx file is compiled with the following setup.py

from distutils.core import setup, Extension
from Cython.Build import cythonize

setup( ext_modules = cythonize(Extension(
            "bulk_phonenumber_finder",
            sources=["bulk_phonenumber_finder.pyx"],
            # extra_compile_args=["-std=c++11"],
            language="c++"
     )))

But i'm unable to get the speed up as :

lines=["0256985412"]*100

# cython version
In [6]: %timeit bulk_phonenumber_finder.bulk_phone_finder(lines)
9.39 s ± 363 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

# python version
In [8]: %timeit bulk_phone_finder(lines)
9.44 s ± 213 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

Do you have any advice to speed up my function bulk_phone_finder ?

Any help is more than welcome ,

Thanks in advance,