Across:
8 Turns up (= reverse indicator), 21st (age = -EGA) party (do = -OD-) is for bighead (‘Big’ head = B-) (BODEGA) making wine in Spain (BODEGA),
9 Imperial crown has no power (‘imperial crown’ has no ‘power’ = imialcrn = CRIMINAL) to outlaw? (CRIMINAL),
10 Dislikes abandoning kids (‘dislikes’ abandoning ‘kids’ = iles = ISLE) in Capri, for example (ISLE of Capri),
11 Foreign politician (-MP-) is about (-RE-) to go to women’s party (-HEN-) in type of school (cod = CO-D) (COMPREHEND) – follow? (COMPREHEND),
12 Fixed (RIGGED) broken (= anagram indicator) digger (digger = RIGGED),
14 Score (MUSIC-) with gangsters (Al Capone’s = -ALS) (MUSICALS) in Chicago and Oklahoma (Chicago and Oklahoma = MUSICALS),
15 For those taking an interest, they’re holding The Euros (SAVINGS ACCOUNTS) – bailing out (SAVING-) some leading (‘Some’ leading = -S) sides? (sides of a story = ACCOUNTS) (SAVINGS ACCOUNTS),
18 Dries veg (dries veg) out (= anagram indicator) (dries veg = DIVERGES) and separates (DIVERGES),
20 Sheds a tear (sobs) dropping off leader (s) (‘sobs’ without ‘s’ = OBS-) on English (-E-) boat (-SS) (OBSESS) with hound (OBSESS),
22 Wild (= anagram indicator) tarragon (tarragon = ARROGANT-) is put down (lay) heartlessly (a) (‘lay’ without ‘a’ = -LY) (ARROGANTLY) in a self-important way (ARROGANTLY),
24 Downsides (CONS) to both sides produced by Coleman Hawkins (both sides produced by ‘COleman HawkiNS’ = CONS),
25 Submissive nature (MEEKNESS) of nemeses (nemeses) working (= anagram indicator) (nemeses = MEE-NESS) over the weekend (‘weeK’ end = -K-) (MEEKNESS),
26 The type of material (SATEEN) for adolescent fighting off cold (‘adolescent’ fighting off ‘cold’ = aesent = SATEEN).
Down:
1 Reviews (= reversal indicator) pretentious (snob = BONS-) brief (r) broadcast (air) (‘air’ without ‘r’ = -AI) (BONSAI) from one little plant (BONSAI),
2 Dig up (= reverse indicator) complete flower sample (‘complETE Flower’ sample = etef = FETE) for garden party (FETE),
3 Spy (WATCH-) on party (-DO-) for Government (-G) (WATCHDOG) Ombudsman (WATCHDOG),
4 Smart Alec misses alert (‘smart alec’ misses ‘alert’ = smac = SCAM) of fraud (SCAM),
5 Scurrilous lost soul (‘scurrilous’ lost ‘soul’ = curris = CIRRUS) with the mare’s tails in The Cloud (“mare’s tails” = CIRRUS clouds),
6 A dark evening (NIGHT-) suit (suit in cards = -CLUBS) (NIGHTCLUBS) designed for dancers (NIGHTCLUBS),
7 It’s seen as a challenge to drop (GAUNTLET) great (G-) relative (-AUNT-) close to accommodation (-LET) (GAUNTLET),
13 Tour leaders (guides = GUIDE-S) welcoming Dubliners, for example, (James Joyce’s Dubliners = -BOOK-) (GUIDEBOOKS) producing volumes of information (GUIDEBOOKS),
14 Names (names) building (= anagram indicator) (names = MEANS) in Capital (capital/ money = MEANS),
16 First (A-) institute (-I-) in Persia (Persia) designed (= anagram indicator) (Persia = -PIAR-ES) (APIARIES) by those with lots of hives (APIARIES),
17 Old pal (CRONY-) is (-IS-) master (-M) (CRONYISM) of giving out jobs for the boys (CRONYISM),
19 The Stones’ (GRAVEL) great (G-) composer (Maurice -RAVEL) (GRAVEL),
21 Burdensome without more (‘burdensome’ without ‘more’ = budnse = SUNBED) from lounger (SUNBED),
23 Pot roasts lacks a port (‘pot roasts’ lacks ‘a port’ = osts = TOSS) to mix around, in the culinary sense (TOSS),
24 State ground is not used in cottage industry (‘state ground’ is not used in/not in ‘cottage industry’ = ctiy = CITY) in New York (CITY).