The English language test is required for the radio endorsement and of course as you need to use radio for CTA you need it for that endorsement. The 2 hours instrument time is required for the Nav endorsement, if flying into CTA requires traveling more than 25nm you need a Nav endorsement. I can't see many people doing the CTA without a Nav endorsement. The rules for Radio and Nav endorsements are below.
61.495 Requirements for grant of recreational pilot licence endorsements
(1) This regulation applies to a person other than a person who is eligible to be granted a recreational pilot licence endorsement under regulation 61.500.
(2) An applicant for a recreational pilot licence endorsement must:
(a) have passed the aeronautical knowledge examination for the endorsement; and
(b) have completed flight training for the endorsement; and
© if the endorsement is a recreational navigation endorsement—have completed, in addition to the flight time mentioned in paragraph 61.475(2)(d):
(i) at least 5 hours of solo cross‑country flight time; and
(ii) at least 2 hours of dual instrument time, 1 hour of which is conducted during dual instrument flight time; and
(d) if the endorsement is a flight radio endorsement—have a current aviation English language proficiency assessment.
Note 1: For paragraph (a), for the conduct of aeronautical knowledge examinations, see Division 61.B.3.
Note 2: For paragraph (b), forthe requirements for flight training, see Division 61.B.2.
(3) The cross‑country flight time required by paragraph (2)© must include a flight of at least 100 nautical miles, during which a full‑stop landing is made at each of 2 aerodromes or landing areas, other than the one from which the flight began.
61.500 Grant of endorsement in recognition of other qualifications
(1) An applicant for a recreational pilot licence endorsement is eligible to be granted the endorsement if the applicant:
(a) holds a recreational pilot licence; and
(b) holds another flight crew licence that authorises the exercise of the privileges of the endorsement.
(2) An applicant for a controlled aerodrome endorsement is eligible to be granted the endorsement if:
(a) regulation 61.480 applies to the applicant; and
(b) the applicant holds an approval from the recreational aviation administration organisation to pilot an aircraft at a controlled aerodrome.
(3) An applicant for a controlled airspace endorsement is eligible to be granted the endorsement if:
(a) regulation 61.480 applies to the applicant; and
(b) the applicant holds an approval from the recreational aviation administration organisation to pilot an aircraft in controlled airspace.
(4) An applicant for a flight radio endorsement is eligible to be granted the endorsement if:
(a) regulation 61.480 applies to the applicant; and
(b) the applicant holds an approval from the recreational aviation administration organisation to operate an aircraft radio; and
© the applicant has a current aviation English language proficiency assessment.
(5) An applicant for a recreational navigation endorsement is eligible to be granted the endorsement if:
(a) regulation 61.480 applies to the applicant; and
(b) the applicant holds a cross‑country navigation approval from the recreational aviation administration organisation; and
© the applicant has completed the following flight time that complies with subregulation 61.495(3):
(i) at least 5 hours of solo cross‑country flight time;
(ii) at least 2 hours of dual instrument time, 1 hour of which is conducted during dual instrument flight time.