Tell my friends to which "comma club" they belong

JavaScript (ES6), 80 bytes

a=>a.map(([s,n])=>s+` is in the ${n.toFixed(n<0?3:4).length/3-2|0}-comma club.`)

Takes an array of [friend, amount] arrays and returns an array of "friend is in the n-comma club." strings. Works by adding extra trailing zeros so that the length is 6-8 for the 0-comma club, 9-11 for the 1-comma club, 12-15 for the 2-comma club etc.

https://jsfiddle.net/cau40vmk/1/

PostgreSQL, 61 bytes

SELECT f||' is in the '||div(log(@a),3)||'-comma club.'FROM p

@x is the absolute value of x, log(x) is base-10 logarithm and div(y, x) computes the integer quotient of y/x.

---

Setup:

CREATE TEMP TABLE p AS
SELECT * FROM (VALUES
    ('John', 100000),
    ('Jamie', 0.05),
    ('Kylie', 1549001.10),
    ('Laura', 999999999.99),
    ('Russ', 986000000),
    ('Karla', 1),
    ('Reid', 99.99),
    ('Mark', 999.99),
    ('Manson', 1000.01),
    ('Lonnie', 999999999999.00),
    ('Nelly', -123.45)
) AS p (f, a)

---

Output:

            ?column?            
--------------------------------
 John is in the 1-comma club.
 Jamie is in the 0-comma club.
 Kylie is in the 2-comma club.
 Laura is in the 2-comma club.
 Russ is in the 2-comma club.
 Karla is in the 0-comma club.
 Reid is in the 0-comma club.
 Mark is in the 0-comma club.
 Manson is in the 1-comma club.
 Lonnie is in the 3-comma club.
 Nelly is in the 0-comma club.
(11 rows)

Jelly, 34  32 bytes

AḞbȷL’⁶;“£ṙƬs⁾`¬ụṂ“¢<ỴȦ8£l»jµ€⁹żY

A dyadic link (function) which takes a list of bank balances as numbers (decimals / integers) and a list of names as strings and returns a list of strings.

Try it online! - the footer çYsimply calls the function and joins the resulting list with line feeds so it has nice output when run as a full program.

How?

AḞbȷL’⁶;“£ṙƬs⁾`¬ụṂ“¢<ỴȦ8£l»jµ€⁹żY - Main link: bankBalances, names
                             €    - for each bankBalance:
A                                 - absolute value (treat negatives and positives the same)
 Ḟ                                - floor (get rid of any pennies)
  bȷ                              - convert to base 1000
    L                             - length (number of digits in base 1000)
     ’                            - decrement by one
      ⁶;                          - concatenate a space with that   ...because -------.
        “         “       »       - compressed list of strings:                       ↓
         £ṙƬs⁾`¬ụṂ                -     " is in the"  ← cannot compress a trailing space :(
                   ¢<ỴȦ8£l        -     "-comma club."
                           j      - join that list of strings with the "number plus space"
                            µ     - monadic chain separation (call that result L)
                              ⁹   - right argument (names)
                               ż  - zip with L